It depends on what you are doing and what your skills levels are.
If you are starting out and have no hosting skills (assuming Linux here), then unless you are ready for a steep learning curve, a VPS may not be for you, especially if you are on a tight budget, as you will need either apache/nginx skills or a control panel to manage them for you.
I wonder how much control you need.
If you chose a CloudLinux host almost all popular extensions are available to switch on, or off, depending on your needs. Ticking/Unticking a box is a lot easier than having to compile PHP with the correct extensions. Also on CloudLinux, your different users (thinking reseller) can all have different combinations of extensions and PHP versions.
As to isolation, an OpenVZ VPS has exactly the same containerised isolation that a CloudLinux user has, only the resource controls on CloudLinux are far more granular than OpenVZ affords the host, so stability and reliability differences fall away.
Just like a VPS a CloudLinux host will be able to sell you more resources should you outgrow your account. And just like a VPS, you will be able to monitor your resource usage on MTRG graphs.
If you want absolute control, then a VPS is what you need, but as previously stated, this comes down to your skill level.
If you are looking to host others and you choose a VPS over a reseller account, then you will be looking for a control panel, but again in reliability stakes (why you may choose a VPS) a commercial control panel like cPanel or DirectAdmin, will cost you extra, but in my opinion deliver you more reliability than an OpenSource panel. Few hosts trust their direct customers to an OpenSource panel, though for commercial reasons offer them to their VPS customers.
Also with a VPS, it will be down to the user to ensure regular backups are performed, whilst with a good hosting account, this happens regularly and automatically. (We backup our customers hourly and offer 3 hourly archives for 7 days, and daily archives for 31 days with a self-restore mechanism.). A VPS control panel would offer you rudimentary backups, but again, it's likely that you will need to rent more space to backup to.
On a VPS, you will be responsible for patching the OS and patching the control panel. This is something your host will have done many times before. They will have full backups and change control to ensure they can revert to a known state if the worst happens.
Ourselves, we rarely recommend VPSs to people who don't know what they are doing, and even if they do know what they are doing, only if they have need of more resources than we are willing to offer on our shared hosting platform.