I went back and forth on this for a couple seasons, mostly because I didn’t want another expensive piece of equipment that I felt guilty about not using. The problem for us was the pool was technically open and clean, but one cool night would drop the water temp just enough that nobody wanted to get in. We’d test it, skim it, talk about swimming, then go back inside. That happened way too often.
We finally added a heater and the difference was less about blasting the water hot and more about stability. The water stopped swinging so much after cool evenings, and as long as the chemistry was dialed in, stable pH, alkalinity not crashing, it stayed comfortable without constantly cranking the heat. I also started using aquadoc natural heat lock to cut down on heat loss overnight, which helped more than I expected with keeping temps steady and not running the heater nonstop.
Result was we actually used the pool instead of just maintaining it. Way more random swims, early spring and late fall dips, and fewer “maybe tomorrow” moments. Is it worth it for everyone? Probably not. If you only swim during peak summer and like cooler water, you can skip it. But if you hate seeing a perfectly good pool sit unused because it’s just a bit too cold, a heater plus keeping the water clean and balanced really changes how often you get in. Curious what climate you’re in, that seems to be the real deciding factor.