Again, this would only affect the cost of making and packaging the physical disc. So even if it were to cost a third more to do that in the US, for example, you might only make the price to manufacture a game go from around $3 up to maybe $4. Game discs are a terrible example to use for potential price increases, since they cost little to manufacture, and making them is not labor intensive. Each replication machine can produce tens of thousands of discs every day, and the process is mostly automated, so labor shouldn't affect the manufacturing costs much. If the options came down to paying an extra $15 tax to manufacture each disc in Mexico (assuming it applied to the full MSRP), or pay an extra $1 to manufacture each disc in the US, the solution that the game publishers would go with should be obvious. It's unlikely that they would raise the price of games by $15 without getting a big cut of that price increase for themselves, when a low-cost alternative solution exists.
Most PC gamers dumped physical media the better part of a couple decades ago, with publishers largely ending physical releases around 15 years ago or so. Any recent PC games sold boxed, like in a collectors edition, will typically just contain a download code for the actual game. And even on consoles, a large portion of games will require big multi-gigabyte patches to be installed before you can play them, oftentimes fixing major issues present in the version of the game on the disc, and in some cases installing these patches is required before the game can be launched. So the benefits of having a game on physical media these days are limited, unless one is lacking broadband internet access for whatever reason.
It's actually a bit surprising that physical media lasted so long on consoles. From looking at the numbers, apparently around 84% of console game sales in 2024 were digital, with only around 16% physical, and over 95% of game industry revenue overall was digital, including things like DLC and subscription services. So it wouldn't be surprising if physical media gets dumped for consoles with the next generation of hardware.
For a leading service like Steam, it seems questionable that they would permanently shut down without warning, leaving users without a chance to install or backup their games. Maybe for some apocalyptic scenario, but then you might have more pressing concerns than part of your game collection not being available. Otherwise, there would likely be months of warning, probably with years of the company experiencing financial difficulties leading up to that. I suppose if one had monthly download limits on their internet service, and terabytes of games, that could be a concern. But again, there is currently no sign that Steam is likely to shut down anytime soon.
As for the PlayStation outage, the service going down for a day or two is nothing major, and one doesn't necessarily need to play games every day. And having the games backed up wouldn't help for multiplayer titles or others requiring access to the servers.
I could see some benefits of having games backed up, like having quicker access to any game from one's library without requiring a full download, or being able to install something even without internet access, but overall I don't think it's going to be much of a concern for most people.