I think there is correlation of *some* equipment to better beer while other pieces of equipment fall into the nice to have category.
An example of two pieces of equipment that I believe helps me make better beer is a very specific length thermowell I installed on my fermenter lid coupled with the temp controller I use to power my fermentation fridge. These pieces allow me to control the liquid temp +/- 2°F of the set point which I think makes better beer. I don’t recall what I paid for these items but I imagine they would be considered overpriced to an outsider.
An example of nice to have would be a power switch I paid north of $150 for. At first glance the price seems high for a simple switch. However, it keeps me from moving the dryer, unplugging it, plugging in my induction cooktop, moving the dryer back, brewing, moving the dryer, unplugging the induction cooktop, plugging in the dryer, and moving the dryer back. Even though it’s overpriced, it’s worth every penny to me.
In every hobby there are the maximalists that have all the latest and greatest equipment and there are the minimalists who pride themselves on operating at a high level on a shoestring. There’s room for both — whatever floats their boat.
I can only speak for myself. In most things, I am motivated by ease of use and cleanup. I have a low PITA tolerance so I’ll spend money to make life easier. I’ll spring for a technology or piece of hardware to solve a problem but once those problems are solved I get content with what I have. This creates a sort of evolutionary process where I use equipment for a while and realize there’s an easier way. I’ve used the same kettle, mash tun, fermenter, kegs, etc for years, but some equipment has been set aside as a new solution is adopted (e.g. I moved from RIMS to HERMS).