As a big Boston sports fan Jon, I'm sure you and Dave Portnoy will have a lot in common and Portnoy I think had a good take (in terms of essence) of how to curb this epidemic currently plaguing football which of course are players dropping just before the goal line for whatever motivations. Write in their contracts if they do it's a million dollar fine. As he said, "guarantee nobody will do it then". And even though that wouldn't practically happen for a number of reasons which all start with the NFLPA, what he is saying tests the concept of "incentive to vs incentive not to".
The IAAF/WA tried this "friendly" approach of the two and even four year ban, presumably with under a "everyone deserves a second chance" narrative - but it's not working. The incentive to dope for athletes of certain nations is still worth it for a variety of reasons and the issue that is "incentive" and "disincentive" factors sit on a wide spectrum depending on where you are from, the culture in society there - so many things.
So dealing with the athletes is the easy part - you can ban them for life, but the problem still remains, for some of these athletes the incentive to cheat and even get away with it for one race is worth it vs a life ban. Take Chepng'etich. She didn't test positive in Chicago - every cent she made from that race she keeps and she also keeps the WR. Even if she was banned for life I would argue that made it worth it for her. On an athlete level you would have to go as far as nullifying all performances in a career and then then more importantly going after money, but I don't know how realistic that is (example if an athlete says "not paying it back" who is filing legal action under what jurisdiction?).
The agents and coaches are the most effective means to make a meaningful change, but also hardest part. It's the only way Rosa (and he's not the only one btw) has gotten away with the systematic doping of athletes for years. These guys run it like drug dealers on the streets run their enterprises. They make the decisions, call the shots, have the connects - but there are always so many degrees of separation at play they can never be directly pinned - modern day Marlo Stanfields.
I'll say this, World Athletics has done an awesome job with the AIU informant system tracking athletes. It's the only way a lot of these top athletes are caught - the only way. But they need to have this rolling on coaches and agents. I get it, it's not cheap and not easy and they only have so much budget for this but I would personally be fine with athletes getting away with cheating for a few years (because they have historically anyway) if that resulted in finding enough juice to ban these guys (Rosa et al) immediately from the sport and make it clear that moving forwards if there is even a suggestion that people are still working with them on any level, they are immediately gone too, no explanation needed. I think then you slowly see a change that will benefit the sport big time in the future vs token gestures that are helping it now.