More and more IP cameras can't be set up without a phone app.

More evidence that this isn't about cost at all, but control. Fortunately, the good old-fashioned "dumb" ones that just have a tiny web server to serve their configuration and viewing UI still exist, seemingly at both the ultra-cheap (unbranded/random brand ones from China based on a reference design, built by companies with no desire to host anything) and ultra-expensive (Axis, Bosch, etc.) ends of the market; the middle is entirely filled with the "smart" "cloud" crap.