That is good point & something I find very consistent with my own experience, as someone who moved a lot (every 5 years or so on average). You think you will be doing this or that, but in reality find yourself pretty tied to place of residence
What really came out of all this discussion is that transport is far bigger issue than I perhaps thought. So let me ask 1 more thing: How much of a gong-show is Nanaimo - Horseshoe Bay ferry? I took that one several times but as a tourist who basically doesn't care. Is it similar to Horseshoe - Gibsons, or better?
I live in the lower mainland but travel to the Island a few times/year and I grew up on the Island so I've taken that ferry many many times.
Nanaimo used to be more of a problem but then they built the Duke Point terminal a few years ago so now there is one terminal (Departure Bay) dedicated to the Horseshoe Bay route and one terminal (Duke Point) dedicated to the Tsawwassen Route.
If you are willing to take an early ferry or a late ferry or pay for a reservation, it's pretty seamless. Towards the end of the day on a busy day the schedule does slip a bit. Long weekends get busy but keep in mind that you will be going against the flow. For example, all the reservations are sold out for Horseshoe Bay to Nanaimo this Friday but there are still multiple sailings with reservations available for people going from Nanaimo to Vancouver.
The problem with the ferry system is that everyone wants to ride the boat on a long weekend but we obviously can't afford to buy 10 extra boats that will only work 6 days/year. As an Islander (and can I infer that you won't be tied to a M-F 9-5 work schedule?), you can just choose to go at the non-busy days. They even have some sailings with cheaper rates if you go off-peak. I've been on a ferry where I think there were only about 15 cars (on the full size boat!)
The cost does become a real issue though if you are going with a vehicle.
How many times/year do you think you will want to get to the mainland?
Edit to add:
Keep in mind that the reservations only apply to vehicles and that even if reservations are sold-out, they do leave some first-come first-serve deck space. Passengers rarely face sailing waits.. but on a busy weekend if can get hard to find parking - I don't know how often the parking fills up.
The key thing is to just avoid the busiest days or to plan ahead and catch an early boat with a reservation.
They publish some charts showing the busiest times.