Long term support is nice but downgrades should also be allowed when one cannot afford to purchase a new one so they will have to go back to a version optimized for the device, it does not matter whether it's Apple, Google, Samsung, etc
Force apple to re-sign at least the last update of the version [iOS 11.4.1, iOS 13.7, etc] and force android manufacturers to stop their downgrade lock... Samsung prevents downgrade once your device is on a certain build/security patch...
Allow users to downgrade to the version designed for their device [or the most optimized], iOS 6.1.4 for iPhone 5, iOS 6.1.3 for iPhone 4s, etc
I don't think you will ever see that happen. Mostly due to legal teams at the various entities. Undoing security patches (even outdated ones) would expose them to litigation if it was ever proved that an old hack compromised a phone in a way that hurt someone.
As an Apple collector (Mac and iOS devices) I find it frustrating that I have to hack my way into my old devices to downgrade.
I see this as more of a marketing push, than real usability.
Long before 7 yrs, the battery would've degraded ( possibly more than once ), newer devices would have more enticing features, new enhancements and functionality (software) may be with held from the aging devices ( see Apple's mantra ), upgraded hardware ( screen, camera, wifi, modem, build etc ) lucrative offers to upgrade, etc. Plus, its Google.. not really a confidence inspiring track record of keeping their promises ( eg: feature enhancement promises getting delayed )
I doubt many folks will hang on to a device for more than ~ 4-5 years, if that.
I disagree.
Part of what Google is doing with the Pixel 8 is making it more repairable with parts availability with partners such as iFixit. This makes battery replacement more trivial than older devices (well except those with battery doors). My mom (for instance) is perfectly fine running an older XS Max and likely will continue to do so as long as Apple supports it.
She has no interest or intention to upgrade that phone, and I am fine letting her keep it as long as she likes provided it has security patches. Her calls, messages, web browsing, podcast listening, and occasional video viewing is all well supported.
I also know people (much younger than I) that only tap into the basics with their phones, and lean to other devices such as iPads, or other tech to do anything more serious. I don't think (many) of these people who hold phones for a long time are looking into 3D modeling, video editing, advanced games or anything of that nature.
For my work phone, I would still be rocking the Pixel 3 if it was supported.