Does a transaction in Bitcoin Mempool reach many miners during mining or only a single miner?
How it actually works:

You send your transaction to one or more nodes (your wallet does this job for you). Each of the nodes (some of them are miners) sends it immediately to all the nodes it knows (and again and again).

All the miners store the transaction (if it's valid) in their own mempool.

When a new block was created, all miners look in their mempool and try to find the best not-mined transactions, pick those with the highest fee per byte and include it in their block-mining-attemp.

If one of the miner's mempool-transactions is mined, they simply delete it out of your mempool.