My folks moved together to Brightview (now Modena) in Bethesda, and are fairly happy--it's a rental; you can give 30 days' notice and leave, which made them feel more comfortable about the move.
That said, the rooms are small and it does feel like a senior citizens' residence.
Of the rental places we visited (my folks didn't want to buy), the only one that didn't feel like a rental was FoxHill
https://foxhillresidences.com/
BUT there's a big difference between those who own (only they can use certain facilities) and those who rent. There were many people who were quite independent, and FoxHill felt huge, so if one person does need assisted living, they can stay there and move "up" a level of care. It was also exorbitant, but everything is.
We also looked at, and loved, Modena Kensington. It's right next to a train station and close to Bethesda. They didn't have a two-bedroom unit for my parents when we were looking.
https://modenakensington.com/?gad_source=1&gclid=CjwKCAjw47i_BhBTEiwAaJfPpsJXVkbPs20gfqSq022c5mVo7KiGtFhzyZ2lYFns6R8tqLAEG47RKRoCykAQAvD_BwE