it’s quite the opposite, updates for safari are generally tied to the operating system so after 7 years (but it could be 4 years in edge cases) safari will stop receiving updates. While third party browsers instead are more gentle, will continue to get updates as long as possible (but it’s still not calculated in “decades” as for windows or linux)
regarding updates, i think linux can be installed on them (never touched one nor plan to do so in the next decade) but the combo shitty cpu+extremely small and slow emmc storage+the bare minimum RAM is a killer. Maybe just for a fun experiment