I recently bought a Oneplus 15R. 500EUR, so just above mid end (Finnish taxes, mid end is 300-400). Current high end SOC (SD 8 gen 5), one of the most if not the biggest batteries on the market (7400 mAH nominal).
They save on other things. Significantly worse cameras, no wireless charging, USB communication standard is only 2.0, etc. I'm not into posting my life on interwebs, and I have a car with wired android auto only at the moment, so I don't really care about wireless charging right now, and I can do most data transfers wirelessly so I'm not too bummed out about slow USB-C port. It worked for me.
Probably won't work for many others.