Bitcoin blocks are mined every 10 minutes on average. No matter how long it's been since the last block, the chance of finding the next block remains the same.* You'll occasionally notice 1+ hour elapse without a new block being mined.

*Economically speaking, a long interblock time would lead to a higher fee reward for the next block, which would eventually lead to more hashrate being produced. But at this stage of mining maturity, you can just consider it random.

Chance. The average time between blocks is 10 minutes, but that can vary because it's probabilistic. If the last block was mined 30 minutes ago, the next block is expected in average in 10 minutes.