The player count fluctuated between just over 8k and just below 19k in the last 24 hours according to steamcharts. There are two things in the works which are certain to bring in new or returning players:

1. Mistlands. A new biome. Hopefully extends the gameplay to at least the same degree as any individual existing biome. It is estimated to arrive sometime around god-knows-which-year. Don't ask the devs; I would say that your guess is as good as theirs but infact your guess might actually be better.
2. The fact that it is being introduced to Xbox consoles. I don't remember if their was any mention of cross-platform multiplayer but the official page for Valheim on the Xbox website confirms that it will come to both console AND PC game pass. I would still recommend getting it on steam yourself because of its low cost and to retain the most freedom for modding later.

Seeing as how you don't appear to have the game, at least on the account you're posting here with, I think it's worth mentioning that if you're planning on playing with strangers you're probably in for a tough time.

This game has some huge timesinking elements and their are countless ways that a negligent or mean-spirited random could set you back hours or days and it would be entirely out of your control. Someone might tour your home while you are away and trigger a mob raid. Others might hoard all of the resources within reasonable distance. One player might rush the current final boss, making the world-state a lot more punishing for new characters in that server. The host might decide they don't want to host anymore and instantly you've lost everything that isn't currently in your characters pockets.

Ideally play solo or with friends in an environment that is closed off from the public, or look for people who say they are willing to commit to the same rules as yourself. Trust is a big thing.