(Retired IT programmer/manager. Many certifications. From CPM, DOS, Win 3.1 .........)
What I have done:
Bought used a couple of Dell 3120's from this site. Think I paid about $70 each.
Chromebooks – iTechDeals
These are CB's coming off school leases. They are beat up a little, and are usually rated as B or C or D stock, mostly blemishes on the outside, completely refurbished. (Whatever that means.) Both completely usable and powerful enough in today's internet environment, web access, online streaming, watching MLB.TV games, playing movies off USB stick with VLC. Here you can try it out, for cheap, and when chrome OS updates expire, 9/2022, for this model you can put a real OS, Linux Mint on it., where you can run real programs.
Chrome OS expire list for other models.
Auto Update policy - Google Chrome Enterprise Help
Sounds like your needs are very modest. IMO CPU doesn't really seem to matter at all. Only saw an issue with playing movies downloaded with H.265 encoding. Celeron N280 @ 2.166GHz. 7 hour battery original, seems to get only about 6 hrs.
Good Luck.