I think pollution and deforestation are big factors here. We are putting so much rubbish into the atmosphere and not realising the damaging effects it's really having, or we are simply to stubborn to take it into consideration. Deforestation is us simply building on land taking food, pollen etc from animals. Destroying their habitats for ourselves.

Over time if bees become extinct the entire food chain will collapse and it can or will impact all life on earth. Although small they make a big impact in all survival

They are decreasing because of habit lose, which holds true for native bees and invasive honeybees.

Viruses and mite infections are also taking a toll, and some pesticides may weaken bees making them more susceptible to viruses and mites.

Cooler temperatures than usual.

I think pollution and monoculture (the planting of single crops instead of multiple crops) are 2 main factors