Windows 7 was a competent OS with low system requirements, a stable kernel, a simple feature set that was well-known and useful, an interface that was comprehensible and clearly conveyed to the user, and it didn’t require extra investment or online accounts, and compatibility options for the really old stuff. It remains the Best version of Windows in my eyes.
8 took away the comprehenisble UI, low spec options, and lack of online service requirements, then 10 further complicated the UI and filled the OS with ads, the then 11 bloated the feature set, added even more ads, borked compatibility, and made the online accounts a requirement unless you pay extra and/or know what you’re doing.