Others include, but are not limited to: power consumption meter at the wall (between wall socket and PC power plug). <- Have that (namely MacLean Energy MCE06 230V/16A wattmeter). Bought it prior buying UPS, to know how beefy of an UPS i need.
Another option is UPS that has LCD display. So you can look exactly how much power is delivered via UPS to PC. Aka how much power your PC consumes. For added convenience, UPS that connects to PC via USB cable, so you can check the power consumption from software, either dedicated one or from HWinfo64. <- Have that too (CyberPower CP1300EPFCLCD).
Demand. High end 30 and 40 series GPUs required robust PSUs, and Corsair is a well known brand. Pricing is up across the board, so even their lower wattage units started becoming reasonable 'budget' options. Pretty much every other budget build ends up with a Thermaltake Toughpower or Corsair RM750e in it. Basic price for a decent PSU is about $100 right now. (A few lower wattage models sitting around $90)
Digital PSUs have always been a high end enthusiast product as well, so I doubt they make those in huge volumes.