I think proposing publicly is coercive. Such proposals are usually not discussed ahead of time, and making the proposal public runs the risk of rejection. The opens themselves up to being devastated in front of everyone, but the power to decide their fate would rest on the person being proposed to. If the proposee rejects the proposer, they would look like a bad person who devastate the poor proposer publicly. It goes without saying proposing in public in hope that element of coercion is enough to get somebody to say yes is an incredibly stupid idea, not to even speak of morality. They will resent you forever for it even if it did work. (Though I suppose some people are messed up enough not to care what they think.)
People should be able to make such an important decisions as carefully as possible without unnecessary outside influence or even eyes on their conversation. It would be less bad if the proposer manages to get the proposee's opinions on public proposals ahead of time.
The proposer in a relationship is usually the guy in the relationship if there is a guy. To be fair to them, guys have been bombarded with movies and TV shows where public proposals work and the girl is swept off her feet from being so happy. Real life is not like Hollywood, but it can be hard to understand fact from fiction (especially for more sheltered guys who don't talk to many women). Women are affected by media just as much, especially when it comes to body image. Men have a problems as well.
Even when it comes to a video game marriage, I am very cautious of public proposals. People often like to trivial feelings which arise from video game, saying 'it's just a video game'. Video games can be a huge part of somebody's life. For some it's their only place to socialize and we all know how lonely people can get these days, especially with Covid and longtime trends like prevalence of social media. Imagine spending time with somebody you enjoy spending time with for most days of the week for years, and you overcome challenges together. While online interactions are not the same as real life interactions, to say they can't amount to much is absurd. Sometimes the person saying 'it's just a video game' is the very person feeling the emotions themselves, as if telling themselves that over and over will decrease the stakes and make them take things less seriously. When it comes to interpersonal relationships, feelings are feelings. They are real, and refusing to deal with it by saying they don't exist isn't helpful.
When I see a person holding a surprise proposal who actually is interested romantically with my friend who I know is not looking for a relationship, I get worried. I don't want her to feel uncomfortable. I want her to always feel okay to say no. I worry that one person does not understand what the other one wants from the online marriage. I worry that he will develop stronger feelings for her when she cannot be invested in people that way right now.
At the same time, it is their relationship. I hope for the best for them.
