Totally agree. I started on a low end Fender Precision ~35 years ago and did fine - then bought a Fender Jazz. As I got better and needed better/different tone & higher volume, I upgraded gear - amp, cab & basses. In the late '80's, I "upgraded" to a Carvin and more recently (last ~10 years or so) I've since paid several high end luthier's to build me instruments.
As time progressed, I've sold most of the custom builds, traded a few others and now have come full circle back to Fender Precisions and Jazz styled basses. I still own a relatively high end Jazz, a Warmoth J, a Fender P, a Breedlove acoustic fretless and my original Chinese made upright (note the upright is almost 30 years old, so I guess it's now becoming antique-ish).
Does one "need" a high end instrument? No. Are high end instruments "easier to play"? In some ways yes, and in others, no. The player still needs to practice and put in their time playing - i.e. having a high end instrument doesn't guarantee skill... Dead notes are less frequent, harmonics may ring out better, it may also fit you or balance better. Thinner/Thicker necks, accurate frets, higher end components and better quality woods MAY make a bass sound & play better. Then again, if the Luthier doesn't have the skill or experience in building instruments, it also may be expensive "wall art".
Much of the gear upgrade-itis is that many have more disposable income and we generally think that we "want" better instruments - cool woods, nice electronics, high end tuners/bridges, etc. Look I wouldn't trade my experience with the custom instruments I had built - they were awesome, played well, looked cool and sounded great - and I paid a good amount to those Luthiers for them too. The Luthiers themselves were awesome to work with and generally had a passion for their work that doesn't happen when you walk into a GC or pawn shop to buy an instrument.
I cut my teeth as a substitute bassist years ago. I knew music theory, practiced a bunch of covers and jazz standards, and I got called. Sometimes I had uber great gear and sometimes i had what I had (read that as not so good). Now I'm a "hobbyist" and play for my own enjoyment. I still get calls and I so some GTG drop-ins from time to time.
Nothing beats playing with others. Play what you own, buy what you want/can afford, practice a bunch and play out. It's all good.
John