What you want is a laptop with a matte screen. Not a "glossy treated for reflection/matte like", which is what you find on most expensive laptops like those from Apple, but actually matte.

It's kind of hard to find because it doesn't sell well because the colors are very much toned down on it, but you can have the sun right behind your screen and it won't matter. I still have one from ~2012 (from the french store LDLC, which are rebranded custome made Clevo) that I gave my GF, and for work purpose and always being at top visibility the screen destroys anything else I've used since.

I'm genuinely weirded out that as far as I know there is no major work brand like XPS or MBP offering true matte screen as options anymore ...

PS: if you haven't seen one before, it's truly no reflection/competition with the sun at all, and it's truly washed out colors.

EDIT: I would at least like to know why I'm downvoted ? A true matte screen is vastly better when facing sunlight, which is what I'm answering to