It's not so much the last few years, but the last 30 or so years - if you go back and watch some of the older tournament coverage (lots available on YouTube from the 1980s on), it's a very different game, with holes of 450 yards being seen as long tough par 4s and long par 3s in the 200-230 range.
The idea of dropping MOI is to increase the penalty for hitting a bad shot - effectively saying 'go ahead and swing it at 125mph, but you're going to be in a world of hurt if you get it wrong', as opposed to 'putting a bad swing on your drive at 125mph means a missed fairway but you still have a reasonable shot at the green'. That means that course setups can be a bit more forgiving without making the course defenceless.
It's also worth bearing in mind that even if restrictions along these lines are implemented, many of the developments in golf club technology will still be relevant and available - for example, we're still going to have lightweight graphite shafts that are much more consistent and reliable than even the best shafts available 20 years ago, players can optimise the clubs that they use using custom fitting, launch monitors and other tools, and iron/wedge grinds and grooves are so much better now than they were in the past.
