It doesn’t require very advanced modeling to estimate a probability of e.g. getting filled at midprice (saving half the bid/ask spread) within a short time period.
Just basic Bayesian with a look-back window.
Execution cost is a big topic in the trading industry.
Some of them are honest enough to realize they're crooks, basically milking their employer for salary which keeps going as long as they shoehorn and manipulate those "backtests" into somehow showing great profits.
I seen these guys. None of these strategies work in real life, they're basically random occurrences on a very particular set of data. Zero robustness that is, you change anything in the data: the underlying index or stocks, the time period (ex: 2015-2020 instead of 2020-2024), the sampling period (ex: 15 minutes instead of 5 minutes), or just (and I was laughing my ass off seeing this), literally one single fucking sample off: start 5 minutes later in the backtest and everything blows to pieces.
And the ignorant public keeps drinking their kool aid because they want, they have to belive in Santa.