Beards have been a fad for several years now, they seemed to become popular sometime in the mid 2010s.
Full beards scream insecurity, and I get the sense a lot of guys have them to overcompensate. The problem is that lot of guys who have beards spend 30 minutes a day manicuring them, have highly stylized haircuts, trendy outfits, tattoos, etc. End result is that most men end up looking like homogenous clones of one another, and they all look faggy and tryhard. The other category of men who have full beards are the "lumberjack" types - I would suspect this is due to the fact that full beards are no longer considered rebellious like they were in the 90s or 2000s, so more men are simply comfortable with them in general.
Nowadays, I prefer the heavy stubble look. Lately I have also been sporting a mustache, and a many women compliment me on it. I predict mustaches will make a strong comeback in 5-10 years.