I have searched few job sites. Many companies are searching engineers who can handle Jenkins as CI platform. I think the Aws CodePipeline is easier than Jenkins.
Anyone can advise me, please. Thank you in advance.
Jenkins has been around for longer so it has a larger installed base. It doesn't matter if AWS has something that is cheaper and better. Many places don't want to put the time and energy into upgrading Jenkins. Migrating to a new CI pipeline is even "scarier" -- regardless of whether it would be a wise strategic decision.
Jenkins 1.x made this far worse because of needing extensions for basic functionality. Different departments wanting different plugins that wouldn't play well together led to multiple Jenkins instances. Even if the technical challenge of merging these were relatively minor, the chance of getting departments that could never agree on anything before to suddenly decide that they can migrate to some new thing -- that is missing some feature from a plugin they can't live without -- seems pretty slim.
Maybe cost is a factor? And it's open-source? I would think those two factors alone make it popular amongst startups.
I work in an enterprise environment and we use AWS a lot but still use Jenkins as our main build tool.
Sure there are better, more polished options, but like I said... cost and open-source, and also many people are used to it already.