There is literally nothing in Seattle between Paine field and Boeing field in the main I5 corridor if you don’t count sea planes (all the airport symbols along the lake are float planes, Boeing field, SeaTac, and Renton are all basically right next to each other). It is a pretty air strip dead zone, you had to go all the way out to Arlington to mention another one (they have a nice playground next to it that the kid likes to watch planes from)! And ya, the boonies have landing strips everywhere (like the one out near Snohomish used for sky diving).

You're clear with no restrictions from about Downtown to North Lynnwood. Even then, as you approach Paine and SeaTac, you can fly with altitude restrictions (300, 200ft, etc). On the eastside along 405, permissible areas are even greater.

https://b4ufly.aloft.ai/?lat=47.124171412997555&long=-122.39...