I've had HTC phones as my last two phones. My Incredible S lasted 5 years (and could've been used longer if the app storage wasn't so small on it). My HTC 10 is still going strong after 6.5 years. It's been repaired once, but I'm very happy with it overall.
I'm in a bind, though, as it's really hard to find phones that aren't largish. Right now, the Zenfone 9 is a pretty decent size for me, and it looks like the Zenfone 10 will be larger. I'm thinking of preemptively getting a new phone because I don't know when another good one will be available, and I don't know how much longer my HTC 10 will last. The only other option I'm considering is a Google Pixel 7 or 7a.
What is the expected lifespan of an Asus Zenfone? I'm a fairly light user, so I'm not constantly recharging it (my HTC 10 lasted 3 days when it was new; I'm still getting 2 days, but that's with a replacement battery). I never drop my phone, either. Can I get 6+ years out of an Asus phone? I've heard they had battery problems in the past. Has that been resolved? Also, how good are they at keeping parts and batteries available down the road (ie. 3 or 4 years)?
If you have any thoughts how the longevity of the Zenfone compares to the Pixel, that would be appreciated, too.
If you're planning to keep the phone for more than 2 years and you care about updates and cameras you should go for the Pixels. The Zenfone 9 is a great phone but Asus offers only 2 years of software updates/security updates and the cameras are not the best. Go for the Zenfone 9 if you care more about battery life, audio, one hand experience and performance . Remember the Zenfone 9 has one more Android (14) Update left.
I've really enjoyed the hardware for the Zenfone 9. Great size and love the headphone jack and side-mounted fingerprint detector. However, the software has not been great. There have been a couple things that have actually gotten resolved, so my biggest complaint now is that the bluetooth doesn't behave as expected. If you search this forum for topics on "Zenfone 9 bluetooth" you'll see lots of posts.
It's hard to predict how long a Zenfone will last. Probably very few people keep their phones for as long as you do. But the Z9 is definitely a sturdy phone with an up-to-date, powerful but efficient chipset.
I've had a Z8 for almost a year and a Z9 for some 9 months (but I have a few other compact phones of a recent or older generation). Both my Zenfones have been reliable, with reliable updates. The bugs I encountered were solved rather quickly for me. Overall, my Z9 is not buggier today than my Pixel 4 or S23.