Meh, I'm just going to keep my beard regardless of whatever the trend is. I couldn't really care less about what's popular or trendy at any given time, nor do I have the desire to be in the know.
I'm rather partial to a nice square goatee these days but that's probably just because that's what looks best on my current partner (I like him a lot). Beards are very similar to haircuts in that they are best groomed with consideration for the person's other visual characteristics such as face shape, overall style sense, and the amount of contrast and undertones of their hair and skin.
So many men would be 500% more attractive if they literally just took a day to sit down and do some basic research into what styles of head and facial hair look best on them, as well as what clothes and colors suit their current body type and how to pick glasses shapes and stuff. It feels like most men are like 5 infographics and a little advice from a friend with decent fashion sense away from being hot as all hell.
Edit: did a little googling and my vagina / feminine libido would like to sign off on Bespoke Unit Even if you're not much for suits, they've got a lot of good info on how to pick the right hair, beard, glasses, etc, and they talk about how to dress a variety of body types respectfully but also without hedging.
...all of the above? They're pretty standardized cosmetology concepts. I feel like you're trying to make a "gotcha" a la modern cancel culture's narrow understanding of beauty standards beyond pure capitalist sales tactics or even just a general philosophical overcomplication of a concept that's actually pretty simple and widely applicable.
There's a lot of basic cosmetic / aesthetic concepts that are relatively stable even across time and cultures, but that are still widely applicable enough that you can account for narrower or subcultural variations.
So for instance face shapes, like I said. Oval faces are gonna look good with the widest range of hair styles, but generally speaking large flat bangs or long unlayered hair are going to sit strangely on the proportions. As far as hairstyles go that barely even counts as specific, but it does help point you in an artistic direction that's most likely to generate a pleasing result to most people.
Now that last bit is where you seem like you want to quibble about (people on the internet LOVE to nitpick casually made absolute statements; its an extremely easy to learn logical concept that you can use to derail a wide variety of otherwise useful conversations) so I'd like to refocus this conversation on my original point:
If you would like to be more broadly attractive to a wider range of people, here's the general style guide from people who have a good eye for that kind of thing. If you'd rather just be an odd-shaped pot and sit around and wait for your lid, that's completely fine too. Often those are some of the best relationships. The issue is a lot of people lack the introspective clarity to accept that weird shaped lids often take a while to find. A lot of these people become rather upset that there's "no answer" to why it's taking them so long to find someone when there absolutely is an answer, just not one that requires 0 effort from them.