The next two show it fitting 20% more data with 2-3x the CPU, which is a tougher tradeoff but still useful in a lot of situations.
The rest of the post analyzes the CPU cost in more detail, so yeah it's worse in every subcategory of that. But the increase in compression ratio is quite valuable. The conclusion says it "provides the highest compression ratio while still maintaining acceptable speeds" and that's correct. If you care about compression ratio, strongly consider zstd.
technically sure you're correct but the actual overhead of lz4 was more or less at the noise floor of other things going on on the system to the extent that I think lz4 without thought or analysis is the best advice always.
Unless you have a really specialized use case the additional compression from other algorithms isn't at all worth the performance penalty in my opinion.
but for vps, where the cpu usage is extremely low and ram is expensive, it might make sense to sacrifice a little performance for more db cache maybe. can't say without more context