Unfortunately for SMBs, it’s usually very hard for them to offer the same opportunities for further training and professional development as the big corporates and specialist IT companies.  This is one of the major reasons why it can be so hard for SMBs to hire IT, staff, in general, and cybersecurity staff in particular.
1. You are worried that you need more breadth and depth of expertise 
Any given employee can be a generalist or a specialist, they can’t be both.  This means that the only way to maximize both breadth and depth of knowledge is to employ a team of people who can supply it.  In some cases, including cybersecurity, this team will need to be quite extensive (especially if you want to ensure that there is cover for staff absences) as well as extremely expensive.
Using managed network security services provides an elegant way to resolve this issue.  You get access to a team of experts as, when (and indeed if) you need them and while there is, of course, a cost in this, it is likely to be much less than you would have paid had you tried to recruit the same team internally, plus you get guaranteed service and don’t have to concern yourself with recruitment and retention issues.
2. You don’t have the budget for best-in-breed security tools 
Best-in-breed cybersecurity tools can be very expensive, prohibitively so if you’re an SMB buying them purely for your own use.  Added to this, you need to know what you’re doing to use them effectively, which means either you need to recruit and retain skilled cybersecurity professionals or you need to find people you can train.  In fact, you may need to train skilled cybersecurity professionals as products are continually being updated to cope with new threats and people need to learn about the new features.
If you opt for a managed network security service, it will be the provider’s job to buy the tools and make sure people know how to use them.  Obviously, they will charge their clients for this, but the cost will be spread across multiple companies rather than just one.
3. You’d rather your in-house staff focussed on value-add activities 
Even if you don’t have a dedicated in-house IT team, somebody in your company has to be taking ownership of IT-related activities, and that somebody is probably going to be spending more time than they would like on firefighting and general administration.  What’s more, if they’re struggling to fit everything into their day, then it is almost inevitable that their results are going to suffer.  
This means that, as a minimum, your company is not getting the best use of the time for which they are paying.  At worst, you could end up on the wrong side of the law.  This could be civil law, for example, if you use a piece of software without the appropriate license (for the record, software which is free for personal use may not be free if used for business purposes).  It may even be criminal law, for example, if you wind up treating personal data in an inappropriate manner.
In short
Basically, if you are finding that running your own cybersecurity is causing you too much frustration and stress, then the best solution may well be to hand it over to a managed network security service.
 Managed networks definition