Ray Franz spoke about the report card in his books as a "means of exerting pressure" on publishers (ISOCF P189) and when the possibility was discussed in the GB about ending the obligation to report , some of the GB members were worried that this would result in publishers doing nothing.
But he also mentioned the essential purpose of the preaching work which was to sell and distribute the Societies literature - clearly a dynamic that no longer exists.
A friend of mine is a "distributor" for a MLM company selling the usual grossly overpriced "organic" rubbish , but in reality she doesn't really distribute much - most is currently boxed & sitting in her spare bedroom or given away as gifts. All pre-paid by her ( with a supposed 20% "discount") . The WTBTS has always pretty much functioned on the same basis , albeit the model has changed over the years. In the days when we paid for the magazines , I can recall countless times having numerous left over magazines that we just gave away as "sample copies" when doing rural rarely worked territory.
With respect to the original poster , I still don't see the Society stopping the necessity of reporting , unless it was an absolute legal imperative. Perhaps they might tweak it ( online reporting would be an obvious cost cutting and efficiency move) or even perhaps make it anonymous in some way ( perhaps citing GDPR or data protection legislation ).
How often did all of us drag ourselves out late in the month if we hadn't been out to "put our time in" , or stay out an extra couple of hours when pioneering for the month? I can think of many times when publishers record cards were passed around the Body of Elders to discuss ( usually to criticise ) the individuals activity. I'm convinced that without this incentive , JWs would do a lot less ministry.
And even though there would be some checks ( such as the elders seeing how active and how often somebody was out on the ministry in the congregation ) this is a very loose tool. We all know the JWs who met at the meeting for field service but didn't go on first call because they were "doing calls" ( usually at Dunkin Donuts ). It is very easy to fake doing ministry for years , especially in a big congregation- I know ,because that is exactly what I did. The reporting tool , though with the inherent flaws of a self assessment audited system , nevertheless is a hugely valuable took to the WTBTS.