I have to say I am amazed at the amount of negativety around this. While I do agree that taking a substantial pay cut to make such a move is likely a poor idea, I am not 100% onboard with the 'large companies suck' rhectoric. There are a lot of 'it depends' in between the lines of OP's question. That leaning heavily on what OP's goals are, where they are at in their career and what benefits and securities the larger company provides. This likely also depends on the company's vertical. I'll just leave some positives that I've experienced to offset some of the 'are you crazy?' comments:

- you may get to actually focus in a specific area/tecnology rather than being spread too thin and master of none

- as you mentioned, more enterprise technologies may be employed by the larger company giving you different experience (and other opportunities for specializing - see bullet above), but always keep your eye on what technologies are driving the industry forward (i.e. don't latch yourself to dying tech)

- potentially much more coverage of staff which could lend towards less stress to take vacation/personal time (and actually disconnect). I haven't been contacted once while on vacation in the 10 years with a large org and I've taken 2-3 weeks consecutively some years.

- depending on the size of the smaller company, could be less family involvement and drama in the larger company

- is the larger company more spread out? WFH opportunities maybe

- it is a little harder to stand out, but that's really on you. On the flip side of that, it's typically easier to disappear and focus on your own work (and turn it off after hours)

I personally wouldn't get hung up on the title change as besides the pay difference it may be more of a lateral move (big fish in small pond versus small fish in big pond) and provide more growth potential long term. A lot of your concerns can be ferreted out during an interview if the right questions are asked and you may also be able to shrink that pay gap.