%%I am not endorsing OP's posts on the object. However, discretionary trading is a very personal thing and I find the humble trend line (more accurately a trend ray) and its clones to be a neat tool.
Reference sources are widely known and available. I've read Schabacker, Gann, Elliott, Edwards and Magee, Sperandeo, Hershey and others. But to make it useful, as with any tool, a repeated religious experience in actual practice is required. A lot of money has to be made with it. This is a very personal thing. People who do not have such experience will never trust it or believe it.
Of course, stating that trend lines are useful and showing that they are are two different things. My viewpoint from experience is that no one who actually makes money will make a demonstration in public, or even show charts like the OP.
In any case, I will conclude by saying trend lines are not subjective but are drawn objectively every time according to rules. They are drawn in advance and they are extended into the future ahead of current price.
Happy Thanksgiving.
Good + good thanksgiving.
I draw straight trend lines[rays] on volume, but I like price-trend lines , i find curved trend lines auto drawn , much more useful.[AKA moving averages]
I dont find his 2 year charts useful @ all, I like longer + shorter, charts but each to his or her own. Some profitable traders[extroverted] post charts; its rare , not much reward for risk.
QQQ all ready took out JUL HI + closed above it all week+ today/11/20-28/2023;
so its a good time to sell[exit longs] also

Can always get back in if wanted

One of several things fundies are useful for -some sectors have huge %% winners+ some sectors seldom do.