i've heard some people who use baking soda and trichlor exclusively and never have a problem.

That is posible in theory as long as your pool has some aeration, a high rate of water replacement, and a relatively short swim season. In practice it is very iffy. The odds of having problems are quite high.

One can also be lucky enough to not have sufficient algae nutrients in the pool for them to grow too quickly in spite of the reduced disinfection rates as the CYA level climbs. The CYA may also get diluted from summer rains, backwashing, and over the winter. It's a statistical risk so the question is, "do you feel lucky?"

Also, some trichlor tabs have copper in them which is an algaecide (but can stain pool surfaces and make blond hair greenish) and some people use supplemental algaecide products to prevent algae.

In my own pool when I got started 8 years ago, I used Trichlor pucks/tabs in a floating feeder. I also used algaecide every other week (a PolyQuat/linear quat mix). The first year was fine, but around the middle of the second season I couldn't easily keep up with the increased chlorine demand and the water started to turn dull/cloudy. It was an impending algae bloom! My CYA had climbed from 30 ppm to 150 ppm. However, I had an oversized cartridge filter, so no backwashing and only one cleaning between the seasons, and I had a mostly opaque electric pool cover where I pumped winter rains into the sewer and not into the pool (we don't get rains in the summer).