Yes, you wouldn't use Sidekiq anymore either because you would have a different ActiveJob backend, but the important part is that you're eliminating a piece of infrastructure (Redis) without the the poor scalability of DelayedJob.
Sidekiq has other useful features (like the built in dashboard)
That’s what CloudWatch is for....
CloudWatch is an awful tool to have to use
Don’t get me wrong, I’m no savage. I use structured JSON logging with Serilog and use ElasticSearch as a sink with a Kibanna for most of my app logging.
I also log to Cloudwatch though and keep those logs for maybe a week.