Solid AKA airless AKA airfree tires are still the thing to use if you absolutely can't / won't consider fixing a flat, and they're still available.
There's considerably more people around who have opinions about them than there are people who have actually ridden them.
These days they're available in different hardnesses to mimic different tire pressures.
I've used them extensively, and I'm reasonably pleased with them.
They don't ride exactly like pneumatic tires, but the overall conclusion I think should be that they're different rather than bad. The hardnesses I've used do give the bike a rattle on uneven surfaces, but OTOH you can cruise in blissful nonchalance over a sea of shattered glass.
Why I haven't gone over to solid tires entirely is:
- there's a limited number of combinations between tread pattern and which rims they'll fit.
- knowing what to expect in feel and handling from a certain hardness is difficult, and you only get one shot per tire
- The hardness changes with temperature, which isn't that nice for a year-round bike.
What most people to is to accept the occasional flat, carry repair equipment, a phone, and/or fare money. Then, depending on riding conditions and degree of concern, you add thick tires, thick tubes, flat protection strips, and sealant in the tubes.
