looking for half-stable Linux distro

Just to clarify, I'm not trying to stand up for Red Hat in any of the following, just explaining the relationship between Red Hat, CentOS, and Fedora. My stance on Red Hat has historically been neutral, but recently is erring towards negative after the IBM aquisition. My stance on Fedora has always been positive.

Probably because of what happened to CentOS.

Red Hat bought out CentOS in 2014. They took over their trademark, hired their development team, and placed Red Hat developers on the CentOS team. CentOS was downstream of RHEL, so Red Hat had an invested interest in it, since it actually resembles RHEL.

That's an important distinction: CentOS was downstream of RHEL, and could be used to replace it in enterprise applications. Fedora is upstream of RHEL, and not suitable for enterprise applications (too many package and kernel updates, everything changes frequently, short term release lifetime, etc.). When CentOS was discontinued in favor of CentOS Stream, it no longer had the same value in enterprise use as RHEL, and its competition to RHEL was mostly eliminated. Again, the most important distinction there is that CentOS competed with RHEL, which is why Red Hat took it over and killed it.

Fedora is entirely community managed and developed, with FESCo being community-elected and making decisions in the interest of the community, not in the interest of Red Hat. Red Hat sponsors Fedora, but that relationship is merely financial. It provides money to the Fedora Project because RHEL is downstream of Fedora, and benefits from its continual development. Fedora does not compete with RHEL, so Red Hat has no interest in controlling Fedora, nor could they if they wanted to with the way the project is managed.

Who owns the Fedora trademark?

Red Hat, of course. But again, Red Hat does not have the means to control the development of Fedora, and they would get nothing but backlash from trying, and gain nothing from it. If Red Hat tried to take over Fedora and were somehow successful, the project could easily be forked and rebranded, with the community currently managing it taking over the new fork and developing from there. Fedora would become stale, and Red Hat would have to manage it entirely, which they clearly don't want to do in the first place. The only significant difference would be that the new Fedora fork would not be sponsored by Red Hat, and development would slow down as a result. But again, this has nothing but disadvantages for Red Hat. Red Hat benefits from the Fedora Project's active development, and since it doesn't compete in their market, they get nothing from destroying it.

How independent is Fedora really?

That depends on what aspect of independence you question. Red Hat has no control over the development of Fedora, as that is managed by FESCo. So in that way, Fedora is completely independent. FESCo and the Fedora Project don't develop for the sole interests of Red Hat; they develop for the community. Of course, Red Hat still benefits from that development regardless, but RHEL specific development is handled by Red Hat, not the Fedora Project, and changes to Fedora from Red Hat developers that would stains against the interests of the community would not be approved. The members of FESCo were elected because the community trusts them to make decisions the benefit everyone.

Financially, the Fedora Project is quite dependent on Red Hat. That's where the vast majority of their funding comes from. That funding is given to the Fedora Project because its development is mutually beneficial for both the Fedora community and Red Hat. That fact won't change anytime soon. The testing, bug fixes, security patches, and feature upgrades from the Fedora community are incredibly valuable for Red Hat, and without a consumer desktop platform to test those changes, Red Hat would be greatly disadvantaged.

I am not saying anyone should avoid Fedora, I can just understand why someone would.

Personally, I can't. At least I certainly can't understand if their reasoning had anything to do with Red Hat or IBM. The Fedora Project is independently developed, and does not seek to satisfy the interests of either of those companies. I can understand someone not liking how frequently the kernel is updated, but then again, you don't have to update immediately if you don't want to. I can understand someone being apprehensive because there is some software available on Ubuntu or Debian, but it isn't released for Fedora. I can understand someone not liking the dnf package manager; it is quite slow. I can understand someone not liking the folder structure of Fedora over Debian based operating systems. But I cannot understand someone disliking Fedora because they hate Red Hat or IBM. As fas as the end user is concerned, Fedora might as well have nothing to do with Red Hat or IBM. Yes, RHEL is downstream of Fedora, but that doesn't affect Fedora in any way, it's downstream, not upstream. Fedora is, always has been, and always will be a community driven project that primarily has the interests of the community in mind. The Fedora Project doesn't care about what Red Hat wants or does with RHEL, as it doesn't affect Fedora in the slightest. CentOS was destroyed because it competed with RHEL (or at least Red Hat believed that it did), and Fedora does not. If you don't like Red Hat then don't use RHEL, CentOS, or any of their downstreams, but don't falsely associate the development of Fedora as being at risk of damage by Red Hat.

Anyone who avoids Fedora because they dislike Red Hat or believe it is at risk from Red Hat is misinformed at best.