The way people play and enjoy D&D varies so wildly, I don't think just popping into a random game with random people would necessarily be fun 90% of the time.

Maybe I'm a Mony Haul type campaign enjoyer and everyone is running their super serious, extra dark and edgy medieval simulation. I would be bored out of my mind during all those 8 hour long fictional political debate sessions. I wanna hit things with various sticks and win fabulous prizes! 😩