Theres so much to add to this - Its not about the bike - if you are fat, unfit and 40, 10 years of Audi driving and a fat bank balance isnt going to make that £8,000 trail centre bike go any better.
As for brakes - so many bikes with disconnected brakes because the owner cannot be bothered to get them serviced or learn how to do it themselves.
Discs? Ha! So many badly set up in the first place. One overspray of oil an they're fooked. One stuck Avid plastic piston, sorry, composite and they're fooked.
Broken frames, cracked frames, blown seals, tubless that refuse to seal due to a manufacturing fault. The lists go on and anyone from 20 years ago would say the same thing then.
Things were different 20 -25 years ago. Cycling was in the doldrums and all terrain bikes were genuinely new, exciting, frowned upon, feared and frightening all at the same time. It was a brave new world and these ugly fat tyred bikes embedded themselves into the subconscious.
Today, there is so little that is a genuinely new idea. Its just tweeks and revisions. 2009 bikes suddenly become unacceptable and ugly while 2013 off the holy grail of cycling to all.
Just ride what you ride - you'll be overtaken by somebody on something very old, or very cheap or very new. I'll overtake you or you'll overtake me. Just be aware that if you overtake me, I wont be muttering 'gosh, I must need a new bicycle to go like that' because I wont, I'll just need to eat less pies and ride more.
Pies (like beer) are fuel, so you therefore need to eat more to go faster.