TL;DR
Change the research in factorio, that it depends on throughput and time and not on number of research items.What ?
Basically, that there is not necessarily a motivation to optimize the own factory an to increase production after initial setup is done. Even with 1 assembly machine for each science pack, earlier or later I can get all research done.While I try to increase production outcome in a train world / high cost setup I research in parallel things. As it takes long time to build a mega factory, as soon as it is done, many researches are already completed... so all the effort to get to the mega factory was done basically for last few research topics. So I ask myself if it is worth the effort.
WHAT do you suggest?
To change this, a new approach could be implemented.
Research items running into a research building directly via a belt w/o insertes.
The research building consumes the research packs, but brings only progress in current research, if a minimum throughput of all science packs is provided over at least (for example) 5 seconds. If my factory is able, to provide such a throughput, I make progress in the research, otherwise the research items are lost or converted into something else (e.g. pollution cleaning).
Also, if I started no research, items are consumed but converted.
For sure, in the early game you can "hack" it by not connecting a long provider belt to the research building and only connect it, when you want to research something. But this would only work for low level research easily, later on, it would be a nightmare to do so, as you need to deconnect/connect hundred of times.
To supply a research building with all necessary sciene packs, the building might need to get bigger to allow multiple belts running in OR each research building focusses on 1 science pack, but need to be in range of another research building handling the other relevant science packs, to start research. So, only of all relevant research buildings are getting the thorughput for their science pack, the research runs.
For example:
1st level automization (to get 1st assembling machine) --> need 10 seconds with a throughput of 1 red science pack / second
Nuclear bomb --> need 600 seconds with a throughput of 36 science packs / second and science pack color (assuming blue belts have a throughput of 40 items/second
So for nuclear bomb you need at least 6 research buildings (1 for each color).
Alternative approach here could be, that you have different research buildings (tier 1 .. n), where late buildings allow multiple belts running in. With that, the necessary throughput for a research could be even higher than 40 items per second.
Why ?
WHY do you think it increases the value of Factorio as a game?From my point of view, this could increase
a) the challenge in the game
b) the long time motivation to optimize the factory
c) the motivation to build larger factories
d) would allow the devs to better control the progress a player makes in the game, so that the player can only research new items after he really made use of the already researched things. For example, it would be impossible to research nuclear bomb without using blue belts as yellow and red belts can never provide enough throughput.