Solarmass FUD.
AppFlyer is generally used for marketing tracking. That's likely used to track how people are responding to in-app ads for Premium, etc.
Google Analytics is likely being used to anonymously report what apps are using autofill so that they know what apps are important to do QA testing on.
Google CrashLytics is likely being used for crash reporting. This is especially important for a security-centered app looking to prevent exploits.
Google Firebase Analytics is probably used to track health of their Firebase APIs, which they use to improve their services.
Google Tag Manager is likely being used as part of normal app analytics where they want to understand better how people are using the app. MixPanel can be used for similar stuff as well as user feedback surveys.
Segment is the least nefarious of all of these, as it is designed for creating anonymous "cleaned" datasets client-side so that the server knows even less about you.
Editorial:
I'll admit that they probably don't need all of these simultaneously, but it's hard to know how much is kept around for legacy reasons. Enterprise apps tend to be a bit of a disjoint mess.
At the end of the day, it's to their best interest to tailor their app to how people want to use it and improve areas that are frequently used. Their only exposure to this is analytics they collect in the apps/plugins for various platforms. This isn't like Twitter or Facebook where you routinely interact with web pages. A password manager is something most people use once in a blue moon to fill in app logins or site logins. The rest of the time, they rely on the app or browser to keep them logged in. So, for Lastpass they actually have very few times that they can collect analytics and have likely decided to make the most of that time when it does happen.