There's usually a few core systems like the CRM, the marketing suite, ERP (in bigger companies) that cost literally magnitudes more than your Slack's and G Suit

There's usually a few core systems like the CRM, the marketing suite, ERP (in bigger companies) that cost literally magnitudes more than your Slack's and G Suites. Even in a small company you may be spending most of your SaaS budget on just the first two. Not that companies tend to have a SaaS budget, it's more like a Sales budget, a Marketing budget, Engineering budget etc. That's why sales and marketing doesn't mind spending 5-6 digits on their software without sweating it if there's clear ROI. Hey, it's probably still cheaper than a single rep or two. If anything, Engineering seriously undervalues their time and overvalues building their own worse versions of popular SaaS software (no, your ad-hoc Lambda function hooked up to send an SMS is not better than PagerDuty), I see it all the time. Software that saves you an hour a month is probably worth at least $1K+/year as an engineer in the US, and most engineering tools are way cheaper than that.