Monroe is way out of the way if you are just going to Seattle from the south. Lynnwood is an inconvenient detour when there's no traffic (read: 8pm-4am) and an emergency only detour during high traffic times.
I do agree with DRasheed that the Seattle-Olympia-Seattle (or vice versa) trips are an embarrassment of the supercharger network. Sure there are probably not a ton of Tesla owners in Thurston county, but we have the 15th largest metro area in the US and its state capital so this is a relatively common route. Also, I believe Seattle and WA have the highest number of Teslas per capita outside of CA. And it's not easy to make this round trip without detouring to either Centralia or Lynnwood. If you have a 75, you're probably fine if you are going down and back in one day but if you drive around the city at all or stay overnight, you are left scrambling for public chargers.