Buffing and Nerfing bots at the same time.

[Conventia]

The biggest thing about belts that make them worse than bots is that they don't scale (primarily with research), as the latest FFF mentions, all of the options have difficult technical issues. Bots have multiple current and potential ways to scale:

1. Cargo size (currently this isn't infinite, but there's no reason why this can't be the case as long as they are capped to carrying at most one stack of the item).
2. Robot speed (this is currently infinite).
3. Charge storage amount (this is currently part of a mod which uses a feature added by Klonan).
4. Charge time/rate (this isn't currently available, but could be added).

All of these make robots more efficient, both in terms of gameplay and UPS. Making all of these infinite, with appropriate scaling would give megabases more variety in research goals (they already skip military research due to combat not being the goal for many megabases).

These researches would allow reducing the numbers for bots initially, while allowing megabases to achieve even better bot performance with lots of investment. Only about 10-20% of users launch a rocket and gating most of these improvements on space science doesn't effect most users and balancing really should be done for the majority of users. Note, less than 20-30% of users on steam are likely to have unlocked requester chests, so balancing based on 30% of the user base seems niche to begin with.

So, my proposal would be to add research for the 4 above improvements and make them scale appropriately and then making bots worse initially would be offset by research for people wanting to do very efficient megabases.

Note: I don't view belts and bots as solving the same problem, even though they both transport items. Belts don't require power, don't get better or worse with distance and can't be improved via research and therefore, don't scale. Bots seem simple but have various nuances which both make them scale while also making them hard to use at maximal efficiency. If they were meant to compete, they're properties wouldn't be so distinct.

[TheRaph]

Ähm ... you may not take users like me into account, who have registered factorio on steam but never played an hour there but loading zip-files and play different maps in different versions of factorio.
So I'm within the 60% of players who have not yet earned the rocket-launch-achievement on steam but I've already launched a rocket in non-steam-factorio
My main game is in 0.15.40 because I don't like to have my base destroyed by some changes in 0.16.xx - But I use to play around with new things in 0.16.xx on extra maps.

[Conventia]

The steam numbers are just anecdotal. The high level point is that most people never get to the point where bots vs belts really matters (i.e. they don't build megabases).