According to data from BTC.com, of the current total of 546,237 mined Bitcoin blocks, 101,215 of them were empty blocks. Empty blocks are defined as blocks that only have one transaction: the coinbase reward which allocates 12.5 bitcoins to the miner. Empty blocks are often seen by many in the community as wasted resources, as those blocks could have contained multiple bitcoin transactions.
For some miners, however, mining empty blocks may make economic sense. As Bitcoin Magazine explains, "When a mining pool receives a new block from a competitor, it needs to perform a few actions: download the full block, validate its transactions and define a new block to mine on. During this - albeit short -interval, so as not to waste hashing power, they start mining a new block. Only the coinbase transaction is included, so the previous block does not invalidate theirs with a duplicate transaction." By mining an empty block, a miner removes the risk of duplicate transactions in their new block, which would instantly be rejected by the Bitcoin network. If the Bitcoin network rejects a block due to duplicate transactions, the miner that mined the block loses out on the coinbase reward, hence the incentive to mine empty blocks.
Below are two charts the visualize the top 10 Bitcoin mining pools, by hashrate, and the percentage of blocks mined by them that are empty.
(Data Source: BTC.com)