Capturing information is useless unless you can access it. Systemd logging does require special decoding.
And there are already several of these decoding programs, plus libraries so that adding support to existing editors won't be a problem. Ergo that is not an issue today and will be less of one going forward.
A version-compatible log reader facility, however, stands a very good chance of not being so easy to get.
Why wouldn't it be? Libraries already exist. So what is going to stop this from being part of most Linux editors and thus most open source ones? Just boot from CD-ROM.
If I sound extreme, it's because I've spent a lot of time with various binary loggers and have found them to be counter-productive on the whole, and especially frustrating when things have gone to hell.
On mainframes and minis? This is going to be a standard system. It is going to be well supported. The situation isn't comparable.
Why introduce a middleman, especially for something that - as I said - needs to be easy to get at in times of emergency?
Well for one thing the middleman is going to be capable of making it easier to get. Moreover the middleman introduces lots of additional functionality which will make the logs easier to use. Also emergency is not the primary use case. Emergency / hardware failure is something that is less important in the world of virtualization. The actual hardware OS doesn't do much and the virtualized OSes will be accessible.
But this is yet another example where a bunch of designers replaced something that was very functional with something new, shiny - and missing critical functions
journald supports text export so it does what you want. The fact that you don't know that should give you pause in your analysis. That being said syslogd doesn't have basic logging functions like indexing, security / verification, ability to prioritize.... It wasn't functional. Certainly it is possible that syslogd is a better fit for you, though I doubt it. But even if that were the case a better fit for you and a better default for everyone on the planet are not the same thing.