US people really agree that poker is not gamble?

It's gambling.

IMO depends how you define gambling.

If you define gambling as a game with built in house edge like slots, craps, blackjack, roulette, etc. then no, it's not gambling.

Most people in the US think it's a game you are certain to lose at.

Chance doesn't affect the outcome in poker? Lol

It's clear that poker falls under the dictionary definition of gambling, but usually when people talk about someone "gambling" a lot or being a "gambler", it carries a connotation that the person is losing money.

Most players will certainly be losing at poker, but lumping poker or other card games (where one plays with money and can gain an edge) in with other "gambling" games that have a house edge is not really an accurate representation of what these games are.

It's kind of funny because movies usually have inaccurate representations of many things, but they have done a good job of correctly portraying poker or other PvP card games as games of skill (despite not getting some of the finer details right).

When I go out to play a tournament, my family always says "have fun gambling" even though they understand the skill involved.

My grandfather was a big winner in fishing tournaments, and my father watches golf tournaments, but still it's gambling if there are cards involved.

If an algorithm can be designed to always beat human players, is it gambling?

Slumbot doesn't use AI. Literally just an optimized CFR algorithm. Have at it: https://slumbot.com/