The driver updates and especially the BIOS updates are recommendations not must haves. If the system is running well then you can probably put those updates on hold until you run into a problem that is fixed by a specific update. The BIOS, unless it is for a security problem, is one that I would let go unless it addresses a specific problem you may be having. I have a 5575 and have done few updates and no BIOS updates at all and it is running smoothly.  The following might help.

And fireberd types faster than I do...

https://www.howtogeek.com/98465/htg-explains-when-do-you-need-to-update-your-drivers/

I assume you are referring to drivers on the Dell downloads, do not use other driver sources.

Ones that are flagged as "Critical" should be installed.  

Others are optional and up to you whether to install them.  Some are issued to fix specific problems, others general fixes or to support new/upcoming hardware and/or software.  Look at what the update does and determine if it affects you, if it does then you should install the update.

+1 on @JOcean reply.  Be very careful what you decide to do on any updates, carefully read what the update is for.    The old saying, "If it ain't broke, why fix it?"  Long story short, when it comes to computers. 

I do update the driver for my Nvidia graphics,  on the Inspiron 7572, via their Nvidia website.  The other laptops, I have not had any driver updates, as are mainly for surfing, e-mails, Facebook, Netflix, some light gaming,  etc, etc,