No. Your phone becomes damaged (DRAM and flash and performance problems due to battery) but the phone itself usually is fine.

I just got a whole new phone out of a failed battery replacement for my iphone 8+ - my guess is the OS installation was just too damaged to accept the battery pairing process and it just flaked out, it was bootlooping and refusing to charge the battery. I got a refurbished 8+ in consideration, and it's actually great despite being a 5.5 year old release at this point. It's not the actual performance level of the phone itself that's the problem, they just tend to become worn out at a hardware level and the phone tends to become unstable. It was showing all kinds of weird software quirks (discord "send" button would fail to appear when posting a meme despite the image being in the send box, and you'd have to tab back and forth to a different server before the "send" button would show up, etc) and all of that vanished as soon as I got a new phone.

While I can't prove it, my opinion is it would have come back over time even if I did a factory reset, perhaps even worse. Because I had the same experience with my previous phone, an Android Moto G first-gen (Falcon), which I owned for just about 5 years exactly (early 2014-early 2019). The phone simply got more and more unstable due to bad flash/RAM and perhaps some glitching caused by the weak battery... first I'd have to factory reset once in a while, then the whole OS would need to be reflashed, finally the installs were being corrupted less than a day after a clean reflash.

The practical lifespan of the DRAM/flash in a phone seems to be about 3-4 years in my experience and by the time things hit 5 years they are so damaged they are unusable even after fresh OS installs/etc. The timeframe is identical for both my Moto G and the 8+, I bet if I'd continued to use the same handset for another year it'd have started corrupting itself even after a factory reset/etc. I don't know why that would be - whether phones are writing certain flash cells too much and they're burning out, or what. Obviously PC SSDs and DRAM can be fine for a decade.

I am very onboard with some degree of refurbishment being a critical element of long-term phone repair after these experiences. They start to go janky at 3 years, by 4 years it is becoming a problem, and by 5 years it is unusable. Even with clean software installs (factory resets or OS image reflashes), it just is not stable. The Moto G I could write off as a fluke, it was a cheap phone to begin with, maybe it was just janky. The 8+ failing in the exact same ways on a very similar timeline (about 6-12 months later due to higher hardware quality) says to me that DRAM or flash is just wearing out over time. If it was just battery performance problems then it wouldn't have failed to re-pair after a fresh battery was installed either.

Again, now that I've got a refurbished 8+ in like new condition, I can tell you it's still perfectly fine as a phone/piece of hardware, it's more than fine enough to run discord and apollo and gmail and banking and all the other things I do day-to-day. It's not the hardware spec that's the problem, it's a particular unit becoming worn and failing.

This also goes to show the importance of long-term software support... I have basically a new handset on 5.5 year old hardware. It will probably be 10 years old before I retire it. iOS is insanely good about that, I am still receiving full software updates at this point, although probably not for that much longer. Show me an Android phone with 6-7 years of feature updates, please. Most androids won't even get security updates for half of that. That is what keeps the e-waste down. I'm sure my handset will be diagnosed and refurbished and sent out to someone else for replacement too, or sent to APMA region for those customers, the circle of life.

I paid $725 for the phone originally (refurb) and $49 for the replacement, and I just got my third otterbox commuter for the replacement case, probably will kill a 4th one over the life of this handset too. So all-up I am expecting to be around $900 for all hardware expenditures for this phone for 9-10 years. Not too awful overall.