I mean…those athletes are representing a political entity. Their uniforms (in normal non-WADA sanction times) are adorned with the same flags as those of the soldiers invading another country, preventing athletes another country from being able to participate in, or even think about, sport.
I understand the desire to see athletes from Russia or Belarus at competitions, but these are two counties that have repeatedly, and flagrantly, violated the rules of the Olympic Movement.
Russia has broken the Olympic Truce three times in only two decades. They’ve also run a state-sponsored doping program, and had numerous other doping issues before and since that program was discovered. They also attempted to manipulate evidence during the investigation into those issues.
Belarus has repeatedly discriminated against athletes on a political basis. They are also actively aiding a country in breaking the Olympic Truce.
Like it or not, at base level, athletes are representatives of their countries in international sports. If your country is engaging in activity counter to the values of the Olympic Movement, it’s hard to argue your country deserves to be included in international competition.