I’ve used mitts from OGK for about two years until I’ve lost them during a house move. (I’m sure it’s somewhere but just can’t find them.) It was a model with padding and pseudo leather. They got minimal care, dried out between rides indoors. When they got smelly, they were washed with shampoo and hung out to dry.
Before I lost them, the palm area was in good shape, getting a bit thin in areas. The padding was holding together, although one of the gel inserts was starting herniate out of place. The textile area covering the knuckles was showing UV damage discoloring.
I’ve purchased Pearl Izumi mitts that was similar, pseudo leather palms with padding. This time the knuckle area instead of textile is made out of lycra like material. I’ve only used them for about two months but seems solidly constructed. These get washed every now and then, but in addition to shampoo, a shot of conditioner as well.
I’m a sweaty, snotty, rider. On the hottest days, the mitts are soaked. On cool days, they’ll get a bit of snot on them too. Yes, it’s quite gross… hence the higher frequency of washing.