Not sure an arbitrary age on who should stand for a world leader is absolutely a must, perhaps a wealth of experience might tip the balance for some, but the law of averages dictates that pushing or post 80 you are possibly on borrowed time. Into that mix comes an inevitable slowing down and feeling more fatigued. There are always going to be the David Attenboroughs of this world who are magnificent but quite possibly a minority amongst that age demographic, if indeed one makes it to that age in the first place.
I imagine many Americans may wish for a younger and more dynamic person to fulfil the role as they question Biden's mental and cognitive abilities. Then again that situation won't be unique I believe there was some suggestion that both Thatcher and Reagan had the onset of dementia towards the end of their tenures.
I still find it hard to believe out of a population of 350 million or so, it's going to be a contest between the odious Trump and Biden again! the latter who surely won the last election on "At Least I'm Not Trump" ticket. Domestically the US seems to be in a mess. Everything one reads about the opioid crisis coupled with mass homelessness, people not being able to afford basic housing so living in tents in major cities. Several people I know who have recently visited San Francisco say it has been decimated, only the highly paid techie people can afford to live there, they work from home so most of the ancillary business are suffering as a consequence of that and the population has dropped considerably under a million now as people move away. In some places small businesses can be robbed up to $1,000 worth of stock without those who do the robbing being prosecuted. Inevitably some fold as a consequence. Then of course tech industries/global conglomerates are laying people off in vast numbers so when those highly paid people become redundant and can no longer afford the high rents either, one can only ponder whether San Francisco, very much a show case city of the US, will become a shadow of it's former self the way the once affluent Detroit has in its decline. I believe the American people are pretty 50/50 as to how supportive they are as to the aid America is sending to Ukraine, particularly as some of the weaponry supplied has ended up in the wrong hands.
As to the recent visit to Ireland, I can't help wondering why the questionable and under investigation Hunter was wheeled out on the recent "aren't we Bidens ever so Oirish" tour, even though they aren't! and boy all that over the top eulogising of the Emerald Isle is so overdone. Growing up Catholic like me when every man and his dog in the parish and at school has some Irish connection and helluva lot more recent than his, no one carries on like that, some of his utterances of " like my granddaddy used to say if you're lucky enough to be Irish you're lucky enough" massively romanticised and overdone, "really we get it! we know what you're saying Joe only don't bother!"
So I'm agreeing with the OP, someone else! but that's down to the American people.