I still remember sitting in my friend Erik's basement doing Odyssey drafts together. Just so you know where I'm coming from, I've been playing Magic on and off for 25 years and have used both MTGA and Magic Online since their inception. Several Legacy, Vintage and Pioneer players play older formats and with cards that are not available on Magic Arena.
Yes absolutely, there is a thriving community of players that use Magic Online. 15 Will Magic Arena Replace MTGO? Do People Still Use MTGO?