Since I have a .223 Rem and a .270 Win, That combination will cover most shooting and hunting that I do, especially with handloads. So why, you ask, do I own 3, .243 Win rifles? Because they fill a need for a wind-bucking, low recoiling large varmint/range rifle. It bucks wind and hits hard. One can also see dirt fly on near misses, not like the .22-250 and .223 rounds.
When shooting my first .243, I was very impressed with the power of the cartridge, compared with the .22 centerfires. Using 80 grain Hornady GMX bullets, it's a formidable deer round to about 250 yards and is used by the grand-kids with good results.
No, a person just can't own one rifle in a caliber that great.
If I can't be with the rifle I love, I love the rifle I'm with!!