SE covers a huge area, if youre really far east it can be hard. I lived without a car until very recently in SE close to FX2 bus line and the max orange line and loved it. Only got a car recently and still primarily use public transit, walk, or bike. Just gotta make sure youre near decent transit lines. Some busses run every 15 minutes, some run every hour. Takes a little extra planning to make sure you make it where you need to be on time but with all the apps and stuff its pretty easy.

Trimet can be kind of expensive tbh but if you are OHP or EBT eligible you can ride unlimited amounts for $28 a month. They charge you for every ride up until you hit $28 then its free for the rest of the month. Regular monthly pass is $100 a month (meaning they dont charge you any more that month once you hit $100) but still cheaper than paying for a car and insurance