The most common challenge we can say is,

1: Challenges of technological advancement.

2: Increased competition / rivalry

Since the world is based on technology, almost all jobs depend on technology. But there are some people who are not very available with this type of technology, making it impossible for them to catch up. Upgrades are also expensive, so many companies cannot afford them, making it difficult to manage and hire good employees. Not only that, but the population is growing and so is the competition. Due to these outside influences, it is becoming difficult to recruit and manage qualified personnel.

There are many more reasons like,

1: global pandemic,

2: Traffic,

3: local acceptance,

4: Political reasons,

And so on.