I'm guessing one of the higher ups at Hasbro told you this? This decision was probably based on an assumption that In-Person Play and Events at Local Game Stores (LGSs) will NEVER be what it once was before COVID-19, so they're taking extra precaution by forcing players to play online exclusively because they don't like the idea of players continuing to play Paper Magic In-Person at their Local Game Store (LGS) for public health reasons. It apparently puts the company in a bad light so it's easier for them to isolate more players for a less desirable MTG experience while trying to reduce the risk of getting sued for potential damages looking out for their own bottom line of course.Quote from Fully Loaded Shaman »Wizards is shifting towards the normalization of nonphysical products, which will be prioritized over paper magic at an increasing rate over the next 1-3 years. By 2025 most players will be online exclusively. This is their goal.
If this really had been an issue you'd think that Wizards of the Coast would've made a public statement about this already so it has to be something else for why they would be wanting to do away with Paper Magic for good. The Secondary Market itself would be my next guess since it's gotten unsustainable to the point where Wizards of the Coast constantly has to reprint specific money cards to make them affordable for players however it's only good for a short period before they spike back to the same demand they had before. By discontinuing Paper Magic certain expensive cards outside the Reserve List will be treated as another Reserve List for collectors with players wanting to purchase the cards to play them being priced out of the game entirely.