Pretty much no keyboard will collect data on you, they are too often made to cost to afford the extra brain power to do that fortunately.

Keyboards are nice in that a good one will get better with age and use as long as it is kept clean (or you are up to the task of cleaning a dirty one). This means you will benefit from getting a used one. What used ones are easy to get depends on where you live a little bit, but if you are ok with something loud I'd suggest a Unicomp (reliable, durable, high quality mechanical parts, made in USA). If you want something quieter I actually really like Mitsumi KFK keyboards, not always using USB but if you are using a desktop it will have a PS/2 plug for the KFK keyboard, they are quiet cheap but shockingly good, not mechanical but Mitsumi just did everything right when making them. You can also just snag whatever looks fun when you search "used mechanical keyboard" in ebay or craigslist, no need to overthink it, keyboard designs that aren't good died off during the cost cutting of the 90s and 00s.

Here is proof that I know what I'm talking about and also proof that you can ask me more questions without bothering me because I like to talk about keyboards: https://youtube.com/@mandarbmax