I usually buy HumbleBumble's programming bundles without much hesitation. There is always at least one book that is worth the whole deal. And the money is going to a good cause.
Mobile book bundle? I don't typically do much mobile outside of the browser, but I'll grab it just in case I get the itch.
Security? I don't make a living there but it's always been a fun hobby of mine. Sold.
Cryptocurrency? Not interested in investing, but I might as well get a deeper dive on blockchain et al.
Usually 10-15 books for the price of one? Sign me up.
Unlike reading a novel, I find reading technical books don't really "stick" unless I invest significant time, right then, using the language and actually trying out what I'm learning.
It is akin to my experience with learning an instrument -- it is easy to get sucked into buying books and watching videos, but it does zero for my ability unless I'm actively playing and struggling with it.
Even if you're careful in checking the reviews before buying, a lot of technical books have only few, questionable ones, and sometimes there are remarkable books behind them nonetheless!