I have used Firefox primarily for a long time, but have always had Chrome installed for specific tasks. I've been working on moving away from Chrome, however, there were three things that have caused me to continue using it part-time: Google Messages for Web, Google Chat, and Google Docs/Sheets/etc. Welp. I finally decided to look into what my options are. Here is what I found.
Google Messages for Web works exactly the same in Firefox. Head to the URL, it provides you with a QR code, you scan it from the Messages app on your phone, and it pairs the two. Now you can access and reply to your text messages from your computer. Done.
Google Chat works exactly the same in Firefox. With Firefox Containers, I am logged into multiple accounts simultaneously through different container tabs. So, I can open the Chat URL into the container tab for the Google account with which I wish to use it, and it opens the chats associated with that account. Further, as I only use Google Chat with one account, I can tell Firefox to "Always open this site in" that specific container, and it will always open that URL with the appropriate account. Done.
Google Drive and associated apps have always worked in Firefox, though, admittedly, they have never been as smooth. There are intermittent features that don't work as well in Firefox. That said, again with Firefox Containers, I am able to access my Drive content with whichever account I want at the time. This essentially takes the place of Chrome profiles, specifically with regard to providing similar functionality when it comes to accessing content in various accounts. As I use Docs and so on with multiple accounts, I have chosen not to assign any of the URLs to a specific container. This allows me to open Google Docs, etc., in multiple container tabs at the same time. This doesn't resolve the feature issues, but it is a reasonable option. Therefore, basically, done.
I have deleted Chrome completely, and will not be using it moving forward for anything. Unfortunately, there are websites I have encountered that do not work properly in Firefox, and worked fine in Chrome. This is a personal choice to lose access to content that requires Chrome. I'm not suggesting it will work for you, but if any of the above are what is keeping you in Chrome, you now know you have alternative options.