Try https://en.wikipedia.org/wiki/Breeze_Airways to not just avoid the 737 MAX but also the nearly as obsolete A320. On Breeze you always fly on a 21st century airliner.

You won't believe it until you fly it, but when you do you'll be amazed that an A220 or E2-Jet feels more like flying in a widebody than flying in a 737 or A320.