Well of course nothing lasts forever, but this is gaming, and in this day and age Sony have zero excuse to not have something in place by now to preserve their heritage.
I agree, and I'll say more about that in a moment.
They just aren't offering them for sale anymore, most likely because there is almost zero demand for it.
There appears to be
some demand, considering how many Sony console fans have been begging Sony for
years to bring over the PS1, PS2, and PSP games to the PS4, much like Microsoft did with Xbox and Xbox 360 games to the Xbox One.
Sony largely ignored those pleas, aside from a small number of PS2 games...which they then totally botched by not allowing PS4 owners to carry over their previous purchases of those games from PS3. Instead, they would have to repurchase those games, and often at higher prices than the ones being sold at the same time on PS3.
Many gamers decided that this was a "consumer unfriendly" approach, and decided not to support it. I myself only got 3 PS2 games on PS4, and all of those were either free or very heavily discounted. Many large game publisher also hesitated to support this.
Sony could have then gone about reevaluating and readjusting their strategy, saying "maybe if we take Microsoft's approach, allow cross-buy carryover, and set the prices the same on PS3 and PS4", then perhaps consumers would be more receptive and appreciative, and start buying them up. Instead, they stubbornly refused to budge. They then dropped the "PS2 games on PS4" initiative entirely. I'm sure the bean counters then concluded, "Oh well, no one must be interested in those old games", which brought us to where we are today.
Sony could
still readjust their downloadable PS2 games strategy. They could also bring PS1 games, PSP games, and Minis (small-scale PSP games, which were also emulated on PS3) to PS4 and PS5. This seems to be what a lot of people want. If they did all of this, then maybe the closure of the PS3/PSP/PS Vita stores wouldn't sting as much. But that's
not a path that they have chosen to take, unlike one of their main competitors, and that is why there is so much grumbling today.