The Steam Deck OLED has been on the market for a few years now and has proven itself to be a worthwhile purchase. The screen is really beautiful, and the battery lasts longer than on the original version. If you need a portable console for gaming on the go right now, it'll do the job perfectly. There's talk about the Steam Deck 2, but there haven't been any official announcements, so you could be waiting for years. Let's be real: even if a new version does come out, first there'll be availability issues, then the price will be higher, then enthusiasts will spend months testing it.
The main things that limit you are two things. First, the OLED is pretty pricey, but if you're willing to pay, you'll definitely notice the difference in the screen and battery life. Second, you need to understand that it's not for every game - demanding new releases will run on lower settings, but it absolutely flies through classic and indie titles. If maximum performance is critical to you, maybe it makes sense to wait. But if you just need a console to play games on the go, the OLED is a solid choice right now.