Specificity and optimization of your hours you can spend is name of the game.

The reason sweetspot is a "thing" is that if you don't have a specific event within a couple weeks, you CAN generate a ton of TSS per week on a low time budget. If you're only riding 5 to 8 hours a week, that isn't really enough time to really exhaust yourself with sweetspot from a fatigue perspective. Hence, why it works. Just transition over to intensity specific to the event you have in the weeks leading up to the event.

Most folks don't ride enough hours/week in what I call a REAL zone 2 to make the 80/20 90/10 idea of polarized work (80% of # of workouts, 90% of time expenditure). I feel you need at least 10 hours a week to spend to make that work.

A lot of those studies about polarized deal with folks with a pretty solid time budget.

IMO, ymmv.