If you're someone that uses Outlook with any frequency, you probably won't have missed the fact that Microsoft would very much like you to stop using the "Classic" version and shift to the new version. Over the next few months, this drum beat will get even louder as the date the "Classic" version is no longer supported draws closer.
According to Microsoft's roadmap, the final push to getting all users moved across begins this April. This is in advance of a date sometime next year in which the Classic version will effectively become unavailable to install for new users and existing users setting up new machines. Finally, a couple of years after that, support for the old version will be dropped entirely meaning it will become increasingly insecure to use as security flaws are no longer addressed.
We know a lot of people are resisting this change, but it's probably approaching the point where you should be seriously considering switching to the new version if you haven't already. Whether we like it or not, we're all going to be using this version in the medium term. It's particularly important that "Power users" or people that use 3rd party plugins at least check it out, specifically because it's likely that some of the features may not be there or plugins that no longer work. In these cases, it will need to be determined if those features will ever be there, or whether those plugins will ever work. Now is the time to be investigating this and finding a resolution or workaround while the "Classic" version is still available to fall back to.
Microsoft perhaps only have themselves to blame for the reluctance to shift across. People dislike change enough as it is, but they probably started the intial push too early a couple of years ago when the new version was lacking several key features. Many of those have been added since, but the damage has already been done in terms of increasing people's wariness on this.
Based on personal experience as someone that deals with a lot of email but doesn't do much beyond that, the new version seems mostly fine now. There currently seems to be an issue with shared mailboxes where it won't show you the latest emails unless you click away from the inbox and back in again, but that seems to be the only noticable problem in my case.