Would number of transactions change if a year from now mining was 1/10th what it is today, or 10x what it is today? Nope.
You have the causality all wrong.
Amount of mining depends on amount of transaction fees, not the other way around.
With no block subsidy, if the amount of txs drops 10x, then there will be 10x less rewards available for miners (actually even less if you go from (nearly) full blocks to never full blocks) and so mining must decrease 10x to remain profitable.
It's worrisome indeed that hero members such as yourself can get such a trivial implication all wrong.