How to detect cheater? (computer help during the game)

If you are good chess player it is easier for you to detect cheater, for you also it is very important for every game what you are loosing send some report for cheating, because it will be not easy for employers to find cheater if you are sending report for cheating in every game. I generally would not report anyone if I will be not sure with higher percentage, and after that I will hesitate because it is not fair if you accuse someone unfairly, I saw from one streamer that he accused every opponent who won against him that he is cheater, and he asked his viewers to send report even just to be sure. (this one is ridiculous for me)
In bullet game normally it is almost impossible to cheat, and I will never accuse my opponent for cheating.
For blitz game it is much easier (but still there is not a lot of cheaters there), if your opponent played almost perfect game, but also sometimes player from various levels are playing very precise, if game was shorter it is bigger probability to be more precise.
If you are playing rapid or classical time control and if you are better player, there is more chance to play cheater (because of that chess masters are generally not playing games of that time control so often.
More cheaters have provisional ELO or they did not play a lot of games, because after more games it is easier to catch cheater. I will continue this theme, I also want your opinion how will you try to catch cheater.

Does the streamer happen to be Aleksandr Rakhmanov?

In my opinion lichess has a serious problem with cheaters.

I don't know how lichess algorithms works to detect cheaters, but the point is that chess streamers almost every week have 1 or 2 people blatantly cheating and lichess don't detect them or do anything.

Otherwise, in the green platform streamers can play safer, there detect algoritms works better. (Although it also gives the feeling that they protect premium users and some of their staff members of banning for cheating).

I could tell you that this is just my opinion, but other streamers (I won't say the name) have explained me that this is the main reason why they prefer to stream on the green platform.

I won most recently over 30 games in a row in rated rapid games, also 8 games in a row in classical.
How is this possible with so many cheaters?

Sometimes there are a few obvious cheaters in big arena tournaments with longer time control trying to win the tournament but otherwise not that many.

A provisional rating has nothing to do with cheating. If you don't play many games for some time in a time control your rating is provisional again. Of course new accounts are more likely to be cheaters but that is something different.

Streamers and their viewers often report opponents unjustified.

By the way it was not GM Aleksandar Rahmanov, he played on green platform, but he during stream always tried to blame even titled players for cheating, I did not see anything suspicious during games, if your opponent played for black like this 1. e4 e6 2.d4 d5 3.Nc3Nf6 4.Bg5 h6 and after that every perfect move to the end of game or with white 1.b4 e5 2.Ba3 and after that all perfect moves it can be cheater.
Player mostly are cheating with new accounts because their old accounts were detected as cheaters.
Most of the time streamers accuses players for cheating without any evidence, but I looked how grandmaster looses to cheater multiple times and he did not say even a word as excuse.

Yes, thank you for the clarification. I too figured that the only two players during that specific stream who beat Rakhmanov were not cheaters, but it matched the description of the streamer in your first comment so thought it might have been him.

My way is to play gambits that are really new, by Youtube gambit makers, or better - make a gambit yourself - that only you know the mechanical series of moves to correct play against it, and if opponent knows them all, he's probably cheating.

Dont bother trying to detect cheaters yourself. Just report and move on and dont make a fuss