Lutron switches are extremely well engineered and responsive. There really isn’t anything else comparable in the DIY residential market. (Just as one example, most switches, including most of the Zwave switches, are engineered with the target of under two second response time. Lutron are engineered for under 1/2 second max.) Lutron is an engineering company specializing in lighting. They hold a bunch of patents and the entire system is responsive, reliable, and works with many different platforms.
One of the ways it gets that responsiveness is by NOT being a mesh system, which is why you see the shorter range for the Caseta line. You can add one (and only one) Signal repeater to a Lutron Caseta system which effectively doubles the range in one area. Whether that’s enough just depends on the layout of your house. Technically it means you can cover up to 5000 ft.² in a perfect sphere, but not many houses are built as a sphere. 
They do have other model lines which can cover many more devices and footage, but that’s a different conversation.
MULTIPLE SMARTBRIDGES?
The official smartthings integration will only allow you to have one smartbridge per account. If by chance you are using an alternative platform, such as Homekit, you can use multiple smartbridges, which takes care of the range issue, although not the expense. But that’s not an option with the official smartthings integration.
DIFFERENT PLATFORMS HAVE DIFFERENT APPROACHES TO INTEGRATION
To be honest, this gets into very personal decisions about cost versus reliability, and that’s something only you can answer for yourself. Wink had a very reliable Lutron Integration, but they overengineered their system and ended up with an unreliable business model, which led to their near collapse as you know. 
Smartthings has historically always aimed more for the sizzle than the steak and always looks great on paper. (Or in 15 foot keynote slides.) And at a great price. In practice, reliability has been an issue with every protocol they support, including the way they support Z wave. Literally dozens of conversations on this in the forums, so I won’t go into more details now, but it is what it is.
If you have a strong technical background and you’re OK with using a third-party app, Hubitat is a tiny company with a system which looks a lot like what smartthings looked like in 2018, but better engineered, no cloud dependencies except for third-party integrations like voice assistants, and a really good Lutron Integration. It does require the smartbridge, but so just pretty much anything except Wink and the long discontinued staples platform. And if you need a good phone app you’ll have to go to SharpTools or another third party. But it’s a good candidate for some people. (And since everything is local, it has the advantage that even if the company goes out of business your main system will still work.)
Let’s look at it the other way around for a minute. If you’re not willing to get the smartbridge, that would mean replacing all the switches you have. Isn’t that going to be more expensive? Or do you only have three or four Caseta Switches in each of your locations?
We should also mention that smartthings changed its integration Model last year. It used to be that companies could send their device to Smartthings an Smartthings would create the integration for it. That’s how the original Lutron and Integration was done. But now, smartthings has published their API, and they expect the device manufacturers to create and support their own integrations. Quite a few companies have done that, but some of the larger ones have not.
In practice, that means that some integrations are stuck with their original version and no one is working on updating it. Lutron appears to be one of these. The Caseta fan control switch was released in 2019, and it doesn’t work with the smartthings integration. 
Smartthings says it’s up to Lutron, Lutron says it’s up to smartthings, and it doesn’t appear that anyone is working on it. (In contrast, both HomeKit and hubitat have added support for the fan control.)
Maybe that will change sometime in the future (the Arlo integration was finally updated about a month ago, although not everyone is happy with it.) But for now, it doesn’t look like smartthings will keep up with future Lutron changes.
MORE CHANGES
You should also be aware that smartthings just announced last month that they are getting out of the business of designing and supporting home automation hardware. They will continue to provide a cloud and an app, but they are turning over the device side of the business to partner companies. Right now that’s Aeotec. Aeotec just released a UK and EU model of the hub that will start shipping in a couple of weeks, but nothing has yet been announced for North America, so right now it’s really hard to find a smartthings hub of any model for the US.
Nobody knows exactly what that’s going to mean for the future. So I wouldn’t recommend going all in on a new installation based on smartthings for at least a couple of months until we can see how things are going to work in this new world. 
FWIW
Official announcement thread: