(Concern) Care of teeth that have undergone nerve treatment

I'm wondering how to properly manage teeth that have undergone root canal treatment since they no longer have nerves.

Brushing diligently doesn't seem enough, so I am also using dental floss regularly. Of course, I also get scaling once a year. However, as I get older, I feel that my gum health is gradually worsening. Maybe that's why even the teeth that have crowns feel somewhat uncomfortable... I'm also curious about how long people typically use crowned teeth after root canal treatment. Of course, it varies from person to person. Additionally, sometimes I feel a tingling sensation in the gums under the crown when I brush, which makes me wonder if it's because my gums are stressed depending on my body condition... I ask for a full check-up when I get scaling, but I can't help but worry a lot. My parents have poor dental health, so it might be genetic and worse for me... I’m curious how community members manage their dental care well! If you have any tips, please share.