You can migrate away from them if you ever want to.
If you self host instead, make sure your server is on its own vlan. Servers are a target for exploitation, and you don’t want the rest of your home devices exposed if your server is compromised.
Note: A Pi probably has the CPU power, but the caching from the server may be more space than an SD card will hold.
Yeah, this is an important point tbh. Vlans alone don't add any security if your firewall doesn't do something to prevent it, as your router will happily forward packets to the next vlan. It should be on a DMZ vlan, meaning traffic is allowed in at the firewall but not to any other internal vlans.