I'm an AR guy, but it's not an exclusive relationship. Pretty much any weapon has enjoyable aspects. Sometimes instead of the AR I'll break out the SKS, or one of my others. Once you find a weapon that works for YOU, and that YOU enjoy shooting, you'll practice with it, you'll enjoy it, and you'll use it well; whether it's an AR, AK, SKS, Mosin, Mauser, High Point, or something else entirely - find what works for you, have fun, and you'll ultimately be more effective than you would be with someone else's idea of a "better" weapon.
It's not someone else's idea of a "better" weapon as you say. Rather it is a fact that cannot be disputed. Firearms technology evolves (It's true), I have a Mosin Nagant 91/30 that I enjoy shooting, it's fun, but to think that somehow the Mosin is more effective in my hands than an AR is in somebody else's hands with similiar proficiency is absurd. Bolt-action battle rifles are done, they simply cannot match modern or even semi-modern semi-auto rifles like the AK, AR, M1A, FAL, etc.
As previously stated, it's not someone's opinon. If you or anyone else would like to compare the Mosin, single shot 12 gauge, .22 LR, muzzle loader, whatever to any viable semi-auto rifle such as the AR, AK, M1A, etc. and come to the conclusion that the former are "just as effective," I'm all ears.
Hardware matters too.