Advertisers are naturally concerned with the paid search performance of their campaigns.
Your paid search performance it impacts both top-line revenue and expenses. Skillfully executed, consistent PPC account performance management will boost the return on your paid search campaigns, while lowering risk. The question becomes what degree of management, and that varies depending upon the environment the campaign operates in, and the stage of development of the campaign. Some ad campaigns can be run without active ad campaign management after post-launch optimization. That's an autonomous or "unmanaged" campaign. It can work in some circumstances but typically it's not the best approach. When campaigns run unmanaged, an advertiser is exposed to additional risk and potential downsides. Optimization opportunities and shifts in the market will most likely be missed.
Automated bidding reduces campaign management time.
The majority of our ad campaigns are designed to be transitioned onto automated bidding, which reduces hands-on management time.  We also monitor campaigns with alert tracking. So it is not uncommon for us to build (especially, smaller) campaigns, then after a couple of months let them run largely unattended, except for monitoring and occasional adjustments. Automated bidding will deliver better performance for many campaigns.  It also greatly reduces the amount of time campaign managers need to spend on a low-level repetitive activity: adjusting keyword bids to meet changing market conditions and campaign internals (e.g. Quality Scores). However, even automated bidding requires some periodic oversight.  Today's machine-learning-based automated bidding provides campaign managers with a sort of "slow-motion" form of bid control. Most campaigns will benefit from some degree of active campaign management.  It is a low-intensity activity for us in most cases and allows us to spot and correct issues before they become a problem. Because of the opportunities we spot to enhance the performance of campaigns over time, active campaign performance management increases the total value advertisers derive from their campaigns.
Performance Management is a No-Brainer
So for all but the simplest accounts in slow markets, we consider some form of PPC account performance management a "no brainer" because the ROI is positive. The question is only, what level of management is appropriate. If a PPC account is driving results that are important to your business, then some form of monitoring and campaign performance management will likely prove beneficial, following launch and initial performance optimization.