Cables matter - Good quality cables do not cost much and nothing to gain beyond that.
Class d is a "digital amp"
Class d has worse sound quality
the "I have 300w (or another ridiculous number) playing through small speakers (tweeters, mids, etc). You might have a 300w amp, but that isn't what will ever be sent to anything but a sub.
2014 F150 Limited -> Kenwood DDX-9907xr -> Helix DSP.2 -> Alpine PDX-V9 -> SI M25 mki in Valicar Stuttgart Pods, Rear SB17's, Sub SI BM MKV's in MTI BOX. Alpine PDX-F6 -> SI Tm65 mkIV, SI M3 mkI in Valicar Stuttgart Pods
I always laugh when people think they need 12g speaker wire or larger to tweeters or even mids for that matter.
Then there's the max current draw vs actual current draw debate. I've been running the same 100a fuse under the hood for 15 years now and never popped it but on paper I shoulda popped it years ago. Most people aren't pulling near the power they think they are on mids and tweets.
They might say "don't try this at home" but nothing about not trying it at your friend's house.