Bitcoin halving is the splitting of the the block rewards from 6.25 BTC to 3.124 BTC and not a total showdown of mining activities. Mining is an integral part of Bitcoin network and as long as miners are getting incentives for the work done, they'll still be in business. Though, it may not be profitable for some after the halving and they may choose to pack up or sell off their mining gears. 

BTW, miners are racking high transaction fees right now from ordinals and runes protocol spammers that are ready to pay to have their transactions go through.