I was just helping my dad with a brand new Lenovo laptop with Windows 11. It felt unbelievable slow and sluggish. Just opening file manager to create a new folder lagged so much it felt like this would have been a 15 years old computer.

While I personally use Ubuntu on my laptop for several years now, when I helped my relative with a brand new laptop (huawei) with Windows 11 I was suprised how fast it was despite being very cheap, I don't remember any version of Windows that had such a performance, at least visually. Out of curiosity, what model does your father have?