KEF ls50 + beefy amp to drive them + powered sub can match most anything you would ever put in that same room.
But the sub will have to carry more of the bottom end as room size increases.
So room size is the main determining factor for how big and likely expensive a speaker need be to perform at the highest level full range.
If Full range not of concern then things are also much easier.
The stereophile class ratings are only useful to a certain extent. It’s always reasonable to question what you are really getting with products that cost way more than others.
But the sub will have to carry more of the bottom end as room size increases.
So room size is the main determining factor for how big and likely expensive a speaker need be to perform at the highest level full range.
If Full range not of concern then things are also much easier.
The stereophile class ratings are only useful to a certain extent. It’s always reasonable to question what you are really getting with products that cost way more than others.