I use boosteroid, which is just steam on cloud. ~4k @ 120Hz for $12/month. No HDR though (they recently removed it). Such a stupid good deal compared to the price of a gaming PC, that I can't really complain. So many data centers with GPU sitting around...
Not just sitting around, available for rent at hourly rates that will add up to a lot more than $12/month if you actually use them! I'm surprised they can offer this service at $12/month with presumably unlimited usage.