Player lycanthropy was a lot of fun in 5e, and the 5.5 monster manual killed it, though the organized play adventure to promote the new Ravenloft book brings it back (so maybe the book itself does? I haven't gotten to read it yet).
In any case, while fun, 5e Classic lycanthropy was definitely overpowered. One solution I encountered was having the player become resistant to non-magical weapons damage instead of immune and just saying they were not fully lycanthropized yet (which maybe also means they can't "bestow their gift" to other PCs yet). Another strong alternative was just leaning into it. Damage they aren't immune to is not hard for a DM to come by, and having them once in a while get to tank against a whole legion of enemies they are immune to can be kind of fun, and saves a lot of rolling. I don't know, if the player controlling the were-character is an inveterate scene hog maybe it's terrible, but I never thought it was a problem.
When my character was a wererat in Waterdeep Dragon Heist the DM just rolled with it, but gave me the consequence of occasional thematic consequences, the most memorable being having a rat-form sleepwalking incident that ended with the character waking up naked on the outskirts of town.