Not sure what qualifies as "high-end" steel these days.
Columbus tubing?
https://masibikes.com/collections/cl...ssico-frameset
Columbus with thru-axle and oversized headtubes?
https://masibikes.com/collections/cl...ssico-frameset
Jamis offers their Quest in male and female specific designs in a range of sizes, your choice of 4130, 520, 631 tubes -- complete bikes under 2,000.
https://www.jamisbikes.com/usa/questseries.html
If you want Disc-brakes, seems the market is more or less limited to 4130 and "All-Road" bikes, but your choice of Kona's, All-City, and Surly; and sure enough, All-City makes some frames (rim-brake) frames of higher end tubing as well (
https://www.konaworld.com/rove_st.cfm,
https://allcitycycles.com/bikes/mr_p...th_anniversary)
BikesDirect has a snazzy looking 853 complete as well (and had a frame-set package too);
http://www.bikesdirect.com/products/...ross-bikes.htm
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These are just production bikes --- then there are the "small production" brands -- Velo-Orange appears popular among the Randonneurs
https://velo-orange.com/collections/types?q=frames;
Slightly more expensive, Crust Bikes (
https://crustbikes.com/product-category/bikes/frames/), Fairlight Bikes (as mentioned,
https://fairlightcycles.com/product/...v=79cba1185463).
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Did I miss any? Oh yeah (
https://www.cyclingnews.com/features...lable-in-2019/) Niner, Ritchey, Cinelli, Bombtrack, Mason, Ritte, Mosaic, Enigma, --- most well outside my budget, and I hope "high enough quality".
Options are great. My problem has rarely been finding the perfect frame, but finding the "perfect frame in my size and in my budget". Nonetheless, I've also lusted after a custom frame more than a time or two, but for now I'm budget-limited to off-the-shelf (and almost entry-level).