In a bull market, I think the TA may not work at some point, it follows certain behavior as the market reacts to the sentiments but TA does work in most cases when the market goes sideways or even in the bear market.

The only psychological in trading is controlling the trader's greed which is why most advice says don't be too emotional about it. Sometimes when a trader can't wait for the right price and just keeps buying and not knowing why, he'll end up losing.