You could do the same by broadcasting your events to all your peers and having each peer save everyone's events.
But this is also a prerequisite to running a blockchain right? This is essentially the mempool. Then you have a layer on top which does more stuff (the actual blockchain part)
Surely implementing only the sending of log event is simpler than also adding all the hashing and consensus stuff(which in practice adds no real utility) on top?
You are claiming that
a blockchain would somehow make it easier to detect tampering or make stronger guarantees about the log integrity (I think you are being a bit vague here honestly)
That a blockchain is easier to set up than my proposed alternative.
Regarding 1: If the other parties just store the log, you just compare what the company provided with what the peers have stored. Then you see EXACTLY what has changed. I still don't understand what it is you claim a blockchain can do here that just having the peers store a copy of the logs cannot and how it is somehow less brittle.
Regarding 2: it can literally be as simple as serving the log from a webserver (with authentication if you only want the peers to be able to read it) and then have the peers scrape it periodically. Or send an email every night. Yes you need to provision infrastructure and integrate with your logging system. But that is the same for hosting a blockchain based system.