The government regulations are both helpful and harmful in saw developments.
If you take a large step back, saws have moved away from some of the super smokey 10:1 homelites and macs because of cleaner emissions regs. That's what brought us some of these more efficient, higher RPM, lower torque machines. I know lots of guys on here like these, but I think most professional timber fallers would rather use a modern saw for the benefits in emissions and weight/ergonomics over these older saws.
If you take a smaller step back, you'll realize that all the saw companies basically procrastinated coming up with new saw designs until the epa regs rolled around. the EPA regs are driving the innovation, to some degree. In countries where they don't have EPA regs or an equivalent, IE south america, they sell the old models. The only saw stihl reworked a bit was the 036 going to a 361 for example, but pretty much everything else, changing up the 210, 290, etc, was all put off until they had to.
If you look at like the development of better AV systems...that was largely brought about by regulation of the european union, when they started limiting the numbers of hours that workers were allowed to use tools that put out very high levels of vibration.
I agree that the EPA stuff has eliminated some really good saws 372, 262, etc, but it has also brought us many good saws 346 NE, stihl ms 261, etc, etc. And look how excited we are for this! And it's a strato saw.