[Concern] Dad's dental implant

My biological father is in his 70s, but he is young and healthy for his age. He doesn't have any other illnesses or pain, but the worst part is his gums.ㅜㅜ When he was in his 40s, he had tooth pain, but he probably thought it was just pain and didn't go to the dentist. Even after that, the pain continued, so he finally went to the dentist, who said that neglecting the gum disease made it worse.

Perhaps because of this, Dad always struggles with it. His gums are weak, and he has had about 4-5 implants, but now that he's getting older, his gums have become even weaker and are becoming loose.

He enjoys eating, so he prefers soft and easy-to-swallow foods, and he always tells us, "You should start this kind of care when you're young."

I had an implant, but my gums and teeth have become weak, and one of the implants is wobbling. Can I have another implant in the area where the implant is loose?

If the gums are weak, isn't the foundation weak as well, making implant treatment difficult?

What is the typical duration of implant use?

Is a denture better than an implant for someone in their 70s?

Dad has had implants, but he still feels like he hasn't fully regained his function and is considering using his own teeth as much as possible or getting dentures. He still eats well now, but because he loves food, it's very upsetting and sad to see him have limited food options and not eat as well as before.