Some of us would rather say "please don't": https://news.ycombinator.com/item?id=32998091
But TFA is about data tables with a sticky header column, a suggestion which really is genuinely useful.
Sticky headers and often a sortable fields functionality.
I've long wanted to see browsers offer modest spreadsheet-like features for tables. At the very least, the ability to sort, filter, summarise, and compute some simple statistical moments (mean, median, mode, standard deviation, possibly percentiles) of numeric ranges. Pivot tables might also be neat.
No reason this couldn't be a basic browser affordance.
Screenshots work on any device with a modern browser and usually I don't want to capture the entire page anyway but just specific interesting parts.
Sounds like your problem are not sticky headers but the "smart" semi-sticky ones that hide or show dynamically as you change scrolling direction, hiding content in exactly the place the user is looking at.