Do co-authors in low and middle income countries (LMICs) really engage in a research paper they are listed?

It's a good question: do co-authors in countries with lower incomes (LMICs) really do the work on research papers they're listed on? And since publishing a lot helps academic staff get promoted, it could definitely lead to fake or biased papers in places with fewer resources.
But here's the thing: adding someone who didn't really help with the research is a common practice everywhere, not just in LMICs. So, it's not fair to limit this question to just those countries.
From my experience, I'd say there's about a 20% chance this happens in LMICs. In wealthier countries, it's actually a bit higher, maybe up to 30%. It's hard to get exact numbers because people do this for various reasons:

And it's not just LMICs where bad stuff happens. I've even seen cases in high-income countries where supervisors took research done by students and gave it to other students so they could graduate, without even listing the original researchers. This kind of thing happens in LMICs too.

So, yes, it makes sense that researchers should look into these issues to understand why they happen and how to make things fairer in academia globally.

In LMIC co authors are involved in the study from the beginning to the ende.
They provide local expertise, access to community and even in the interpretation of the findings.
Eg. In my study for my masters graduation my advisors were considered as co authors.
They have involved in each portion of the paper, commenting and even during the manuscript development and publication

I agree. 90% do not contribute. Some give little or no advise. However, PhD supervisors do give some useful suggestions and editing. Rest are added out of obligation in direct or indirect ways. This menace will stay, no one can do anything about it. However the journals can put some conditions such as the number of co-authors shall not exceed more than a prescibed number, say 3 or 4. The rest must be duly acknowledged mentioning their contribution. Further in experimental projects some other guidelines may be set ulike academic or applied research. Their may be other domains which need separate guidelines.

The issue of adding coauthors to a paper without adding value to the work is a critical issue nowadays not only in the LMIC but also in the developing countries. 

I think the question, in itself, is insulting and offensive to those of us working as researchers (and publishing) in LMICs. It implies that we lack the integrity of those in HICs.

"Let's be honest: asking experts to donate huge amounts of time for peer review is becoming unrealistic. The current volunteer system is struggling. Journals face delays finding reviewers, experts burn out, and vital specialized knowledge gets missed. Reviewing is demanding work requiring real expertise, often equal to paid tasks. Sure, paying reviewers raises valid worries about bias, costs, or turning scholarship into a transaction. But modest compensation? It's a practical way to show respect for their effort, encourage thorough and timely reviews, and make the system fairer. Recognizing this essential work financially is a crucial step towards keeping research publishing robust and reliable."

Sometimes authors are added to papers in LMIC without much contribution to it, but I do not think that this only happens in LMIC. For reasons mentioned in previous answers, this is a practice that is common all over the world. It is difficult to have a good estimate of how often this happens, but it is not rare.

In my experience LMIC colleagues contributed as much or more to research effort, either in the field or on the intellectual/editing side of the work.