An experiment found that selfing” monkeyflower plants lost 13 percent to 24 percent of their genetic variation compared to another group that were propagated by bumble bees.
Genetic variation is important to respond to changes in nature or the overall environment. The good news is that they used bumblebees and though they claim they are in decline, evidence does not show that, so the plants are not at short term risk. Even better, pollination is not done by bumblebees alone, there are over 25,000 species of just bees, and lots of other insects pollinate. An experiment outside a closed greenhouse would show that.