The problem with enterprise software is that the design, especially the user experience design is almost non-existent. The thing becomes clunky, it looks like it was carved into clay and makes your work perceptibly harder rather than easier. You don't feel like it actually helps you and you hate it. Most of this comes from thinking on personal level in both managers and developers and I have seen some of it first hand. When you have 5 investors and in a team of 10 people everybody has a lofty title, you get kick-off meetings that last for hours and you will get nothing done that is actually good (i.e. helps people do their work). It also doesn't help, that enterprise software development basically spends other people's money. If the developers actually had a stake in the software being actually successful (by sucking less) and could influence this through their work, you would probably under the lead of a great UX designer, get a useable product or service.

If you think, Gmail is an example of great software, we must have very different views. It has UI elements basically on three sides of the screen and basically useless information at the bottom. This includes much space you use on the left, "Program Policies" and "Powered by Google" in the center and Account activity with Details on the right. You have chat windows to the left but they are using the different chat (Hangouts?) that is actually en vogue at Google currently. If it is a GSuite account, Meet is totally at the bottom even if it currently is perhaps the most used tool besides Gmail and Search.
The hamburger menu besides the Gmail logo only hides the left menu with chats and email folders.
To the right, you have something like a start bar where you can access other Google Apps with a single click. The same is accessible with another click from the 3x3 dots menu. Then there is the settings button, which opens quick settings where you also click again to see All settings. You can also click your avatar to switch between accounts, manage the account etc.
You also have further elements above the email listing.
There are perhaps a 100 elements that can do stuff not even counting anything in the email listing. Way too many options to tune everywhere. It is overwhelming and most of it isn't really essential. When Gmail loaded, the app is quite fast so that is a plus. The animations though are not very appealing - they are not physical (e.g. there is no acceleration/ deceleration), this is a problem with Material UI and keeps some people (e.g. my co-worker) from using Android. They feel unwell when they see it. Google could easily fix it in a few months of engineering of 1-2 people but they haven't. Instead, they are inventing "smart" features that you have to opt in or out, because the designer cannot actually decide stuff and take responsibility for those (in)decisions. That is the same with GSuite asking if you are sure you want to send an email outside of your organisation of ~ 4 people. Yes, in such an organisation, it is very likely, you will communicate most of the time with somebody outside the organisation. Where is the pattern recognization when you actually need it?

Also related to the usability of Gmail e.g. on the home turf of Android, in the Gmail app, is they keep auto-correcting text to something totally else extremely badly. I know quite well what I type, especially when typing capital letters - e.g. an abbreviation. I don't want the autocorrect to touch it at all, maybe suggest an edit but don't ever change it without asking. Writing any length of an email on Android quickly becomes unbearable - several times, I even considered not having a smart phone altogether because of it. On the other hand auto-correct isn't able to suggest grammar corrections or better words. Quite surprising how a company specialising in analysing data isn't able to come up with solid dictionaries, discern declinations in some languages, not able to analyse the context, not recognizing grammar. Somebody will say, "autocorrect" is a different team on Android, in Chrome etc. That is bullshit. You should talk to each other at Google and fix your product and service not search for excuses.
Btw. Microsoft was much better at autocorrect in like 2012-2013 on Windows Phone, which worked just much better concerning the autocorrect. Generally, autocorrect there worked to improve my occasional typos and didn't make my writing worse in like every third sentence.

Email notifications with good WiFi and mobile data on a rather powerful phone are hit or miss on some phones as well with Gmail (and GSuite). If you then open the app, multiple older notifications pop up at once.

I don't know about Salesforce, but Gmail is quite a low bar for enterprise software to surpass. I think, the aspiration should be much greater.