One thing that I have not seen brought up in this discussion is how the assumption of a longer campaign. My one recommendation is that if you are having trouble finding players or players flaking out, perhaps put aside the idea of running a campaign for now.
I have had a lot of success getting people to show up for one shots. After you run enough one shots, you'll eventually identify a few regulars who will have the interest and ability to commit to a campaign.
That said, I really love running campaigns. My last campaign ran for five years. Session zero was in November 2018. Last session was in December 2023. But I already had a stable group that have been playing together for years by that point. I would never try to find a new group of players expecting or even hoping for a 5-year commitment.
The way I got to this group started in 2014. I knew that I wanted to start playing D&D again. I loved what I saw with 5e and I was also interested in creating a homebrew setting. I also knew that I preferred longer sessions, but that work and family life would create scheduling challenges. Longer sessions were more important that frequent sessions for me. I also had some old friends that I would regularly get together for board games after I had moved back to the US a few years earlier.
So I decided to run a home-brew campaign where each session would be a complete adventure that would tie into larger plot lines in the campaign. I decided on 8-hour sessions to be run one Saturday a month. Which Saturday the next session would be scheduled for would be decided at the end of the current session. That Saturday that the most people could attend would be the date set. Because of the 8-hour sessions, I could generally reach a satisfactory conclusion for a session's adventure where a missing PC wasn't going to be an issue for the next session. It also made it easy to bring in guest for just one session. So people could invite friends.
I had a seed group of two players who were old friends that I already got together to play board games frequently. Then I wrote out a pitch for my game, that detailed the setting, the themes and type of game I ran, and clarified any class/race limitations, which option rules would be used etc. I also clearly explained the somewhat unusual session scheduling. I posted this on one of the more popular RPG meetup.com groups.
I had quite a bit of interest and after a quite a bit of back and forth over e-mail, I had a group to start with.
I ran the game from my house. Parking was not an issue. My finished basement gives a nice separation from the rest of the house, so I'm not putting out the rest of the family. I have a small kitchenette with frigerator, small stove, microwave, sink, and a good amount of counter space. So we'd regularly do pot lucks. But there are also plenty of fast food places nearby for sessions where we didn't do potluck. The privacy and lack of distractions and noise from a FLGS, and not having to worry about ensuring a spot to play from session to session makes it easier to run games in person.
Over time, we had some people who stopped attending, and new people who were brought in (friends of existing players) and eventually settled into a group of 4 core players. These players have been consistent for over 6 years now, with an occasional friend joining in for a session. Because of work and moving, I now have to run the game online. But it is more important to be able to continue playing with the same group than trying to start over with a new in-person group.
In my new area, I found a FLGS I really like and will go there as a player for oneshots, but my life makes me the flaky player. I just can't commit to regularly scheduled game. As much as I would like to. I find that running an 8 hour game about once a month (some months we fit in two Saturdays and rarely, maybe once a year, we have to skip a month) and time time spent prepping the game is enough for me, along with the occasional one shot at a FLGS or through Start Playing or the Roll20 find a game. I prefer playing in-person at the FLGS, but it is easier finding a one shot, especially on short notice, online.
This is a very long-winded way to say put aside the idea of a campaign and regularly scheduled game. Run a lot of one shots. That will allow you to meet more gamers, have a change to play with them, and hopefully be able to find 3-6 players who are willing and able to commit to a schedule and a longer campaign.