Formula One (F1) - formula in the meaning of directions/recipes with technical and sporting regulations defining it – representing those directions/recipes
One (1) - as first, unique, ultimate... there are and there were other formulas like Formula 2, Formula 3, Formula Ford, Formula Renault…
"What technical reason is it that named it Formula 1?"
Probably because it sounds really cool.........
Originally, I believe it was called Gran Prix racing, and there were no rules. Things started to get out of hand back in the 30's, so they had to come up with a rules "formula". Thus the top level class naturally became formula 1.
Historically though, the cars that were the most impressive performance-wise (at least in my opinion), were the CanAm cars. Imagine driving one of those 1200 hp, turbocharged, 12-cyl 917 Porsches. It must have been a 10+ on the pucker meter!