My first job was at a small private company. They were frugal about spending money on tools. I recall being frustrated at having to spend time wandering around looking for tools. I had a notion to bring my own tools, but my colleagues told me it wasn’t a good idea because with tools in short supply they would be easily lost to well-meaning people who would borrow them and forget to return them. The company eventually bought me new tools, provoking some resentment from other employees who didn’t have new tools. I had no idea at the time that the on-the-job training I was getting in circuit design and debug was worth way more than the cost of some tools and books.
In retrospect, I can’t imagine why I didn’t use my own tools. Even at a company that is short on tools, if you keep them in a locked toolbox, they’re not likely to be taken. A very nice set of electronics tools can be had for under $1,000. That is a modest amount for an engineer. Even for people working at full-time jobs that claim to provide everything an engineer needs, engineers are still paid for getting things done. The employer may not notice time wasted searching for tools, but that time is money/experience lost to the engineer who could be using that time to design new technologies.
All engineers make their money by causing things to be worth more than the sum of their parts. Tools and books are a cost of being an engineer.