Does mean at some point my MacBook Air will stop functioning?

Not at all

my macbook air form 2010 is my only laptop i use now.

I'm running Mojave and can perform many tasks in 2020 like photo editing, video playing and watching sports online.

actually the MacBook has not run this well since Mountain Lion

mavericks -high sierra gave the MacBook some stuttering problems.

anyone can enjoy their MacBook for a long time

You MacBook Air will keep working. If you can't download the newest OS, it keeps working with the latest OS that is compatible with your MacBook Air

Yes.

Nothing.