Yes, but I mean the percentage of power loss of the original petrol-power might be higher for a 2-stroke-engine, mainly due to less sucking action and thus a lower level of generator gas fed in the engine.
Usually 2-stroke engines get the same power at lower revs than a 4-stroke in the case of “working-horses”, or higher power at higher revs “race-horses”.
I disagree in some respects. You need engine oil for a 4-stroke engine and for your transmission as well. OK, this could be more easily recycled and filtered, as it is not burned or lost.
And there are some special mixing oils for marine engines or chainsaws which are biodegradable.
With good oils, you can easily reduce the mixture ratio. I did this on my 2-stroke motorcycle from the 70s. Originally 1:50, I used 1:75 with no problems at all, but much less smoke. 1:100 with modern engines and oils are no problem, some run even with 1:200 for water cooled engines with special oils.
With the emissions: If you would put the same effort for low emissions (catalytic converter, petrol injection, …) in a 2-stroke than in a 4-stroke, there is not much difference.