You described the US (regarding not signing, you are mistaken about the signature aspect). Most places stopped accepting signatures several years ago. Card readers are almost always 'insert' except in the very rare case where a card doesn't have a chip. Tap and pay is not common, however tap and pay is more common than signing something (in the US companies have been resisting tap and pay due to higher transactional rates). I haven't signed for a transaction outside of a restaurant across 17 states and 4 years. As I mentioned above, the last place I did sign for a transaction was in Canada.

Still no PIN as in the UK and Europe (and maybe most of the rest of the world, though). If you steal a chip card in the USA, you can use it. Not so elsewhere.

Every store I have been to in the last few months is tap to pay. It really seems to have exploded in popularity in 2022.

That's not quite true. I have a USA issued corporate card from Citibank which has a PIN. It only gets requested on rare occasions though, typically at automated terminals.

http://www.citi.com/chipandpin (note, pdf link)