the key to realize is that this strategy only makes sense if you have a considerable fraction of total hashrate. If you have 10% hashrate, delaying for 1 block period gives you a 10% chance of finding another block on top (that no one else can search for because you haven't published the first one).

But by withholding you also increase the risk that your first block will never end up in the main chain (if the remaining 90% find a block while you're withholding).

And you would sill have 10% chance of mining another block if you don't withhold.

What advantage does withholding give you?