There’s nothing wrong with argument! Healthy debate is encouraged here and this thread has been entirely that. I’m not saying anyone is being too argumentative. My issue is when threads are framed as discussion (e.g. if you’re investing, should you always go for sealed product?) and it quickly becomes clear the OP wants to argue a position (investing in sealed is the best investment because line go up). Again, there’s nothing wrong with that position, I just wish that was made clear from the beginning.
This is going to sound condescending, but it’s the reality. The type of investing the OP is talking about (buying double-digits of modern boxes at MSRP) is like single-A baseball. It’s the rookie leagues. The OP is absolutely correct that at their scale, they don’t need to think too much about storage, don’t need to have in-depth plans for liquidation, and will likely see respectable returns on their original investment if they buy the right sets and wait enough time. The OP, as well as the community of small-time investors on r/PokeInvesting, will be relatively well served by this strategy. However, those returns won’t be as large as the returns experienced by others.
The investing that others are talking about is the major leagues. When you have 4-5 digits of boxes, more available capital, and have been buying sealed for many years, you have more issues. Storage, selling, price ceilings, etc. become such a large issue that other items (and actual investment products) become much more appealing. More experienced Pokemon collectors/investors don’t have trouble making money on Pokemon. Instead of just doing things that will make money, they do things that will make the most money. Indeed, many of the people here with the longest experience who buy both sealed and singles (this is true for myself as well) have seen the largest appreciation on items other than sealed boxes.