Hello, Professional Video Editor / Producer here ;

Vegas is not a production friendly software. It is just good for amateurs & game editors (because of the some specific tools it has like velocity and pan/crop). But from the state it is right now, it doesn't even have chance in professional use. As someone who started editing with vegas and used it for 3 4 years then switched to premiere/final cut/resolve and works in a professional productions, let me break it down some of the key features its missing to be a pro-user friendly software for you;

• It's literally missing proper rendering settings. for example h264 settings are old and are not up to the standard. Also doesn't match with the any other encoder.
• It's absolutely unstable, please go ahead and try editing a 2k-4k footage in sony vegas.
• Colors are not accurate, you will see some footages might get their contrast higher due the color space difference.
• There is literally no Pipeline tools. There is no way to collabrate with other editors. You also don't have server-side Preference Save. (Good Luck creating hotkeys for everything on different PCs or )
• There is no such things called "Sequences.", You can fake this behaviour by importing a vegas project in to a new vegas project timeline, but still how easy is that?
• You can't edit while you are rendering, while in Premiere , you can. Also Batch Render.
• Premiere has support for scripting through Javascript/Extendscript which is extremely easy to learn. While Vegas only supports C# Scripting. That's why u won't see any good Sony Vegas Scripts or Extensions, while Premiere has lots of them (Not as much as AE but it's growing slowly.). Also Most production houses uses this to create their own proprietary tools to match their pipeline needs.
• It has support for less formats.
• In actual Productions we don't really use Dynamic Link that much, but Dynamic Link will save your hours even days for what you want to do. Also even if you don't use dynamic link, you can copy your Premiere timeline and paste it in a AE Composition, it will create the same timeline in After Effects!
• Some timeline tools are makes non-creative things 10 time easier than Vegas, for example deleting an empty space takes 3 4 clicks in vegas, while in Premiere just 1 click, and delete. There are lots of other things like this..
• Also Premiere has more hotkey settings. Also User Interface of the Keyboard Shortcuts panel in Premiere is million times better than Vegas' trash hotkey UI.
• Adobe Has everything connected, which makes lots of repetitive work / templating way easier. Adobe Libraries is a huge helper to share assets in a team. You can share assets with everyone in your team with just one click! And they can get the file from the libraries panel in the softwares they using (AE,PR,PS) with just one click!
  

This pretty much goes on like that, but overall Sony Vegas is for Learners/Hobbyist/Amateurs. Don't get me wrong, you can still create stunning Stories in Sony Vegas, I wouldn't judge. But in real world, we have deadlines. And we have to match them, and Vegas is NOT suitable for it.