I like your thinking here
Plastic is a byproduct of petroleum, and paper of course is a byproduct of trees. Do we cut down more trees to make paper bags or do we use plastic that comes from petroleum and eventually pollute the environment with the waste.
I'm not sure how deep your knowledge goes, and so my answers try not to assume one way or the other, but there are important and deeper questions than just what appears on the surface. So I write this as much for the general readership as as any "answer to you personally".
Firstly with cutting down trees, there are plantation trees and there are virgin forests. These are different in nature and support entirely different habitats. Plantation forests are none the less a "sustainable resource" (just for reference you have no idea how vexing that term is to me, but that's quite the essay which I have no intention to write and its very well covered in "the literature
" for anyone who's actually interested).
Japan for instance is well wooded (as BTW is Finland where my wife was born and earned her Masters degree in Forestry) and is a very good balance of native and plantation wooded lands.
This link gives some good data on that (for brevity I'll not cite it here)
Finland also is big in paper (being home to #4 paper production company Stora Enso).
What's often missing from this discussion is anything other than CO2 these days (sad if you ask me, that the scope of the problem has been dumbed down to just one indicator). However its conveniently ignored by the public (but well known to industry) that recycling paper has chemical waste issues. I would suggest this reading as a starter on the topic:
Research just published by the US Environment Protection Agency has found that recycled paper and construction materials “contained greater numbers of chemicals than virgin products”. Some 733 identified chemicals, including flame retardants, solvents and dyes, “had greater occurrence in...
The simple fact is summarised by weight however; so plastic bags weight a lot less than paper and so per bag there is (as you'd expect) less issue with all the negative by products than paper.
Lastly there is the inevitable end of life, which few countries actually do in a sustainable or responsible way. Many woke folk think that taking their plastic to a "recycling center" actually doe something good. To believe that you'd have to have a narrow view and not delve into what's behind the storefront.
To me (as a summary) I think that only Sweden does the right thing with plastic waste: turn it into energy by burning it. Burning it in well constructed modern furnaces which either destroy any dangerous chemicals (dioxins come immediately to mind) or capture it.
If you think that waste subcontracted to India is properly recycled I suggest you go on a holiday there and find out. Myself I've been there (for business) a few times, often for 3 or 6 months. The feelings after returning from one of those trips is expressed here (although not related to this topic specifically)
I've just come back from India from my second trip, and (again) I feel troubled by what I see there. Pollution is getting worse and poverty ...
So in my view reduce reuse recycle and proper thought put into all aspects (by government if not by individuals). Bad decisions stem from only knowing a small slice of the information pie chart, and we see no end of bad decisions (usually reactive in nature) from government and the woke.
Personal Disclosure: I completed my Research Masters in Environmental Science in 2007 after having been involved in Environmental Education for about 6 years before that.