'More modern' these days appears to be the 'thousand papercuts' approach - many SaaS products that collectively provide the same feature set.
It's still hell, just a different kind of hell.
Bespoke is a genuine competitor. In the UK it's not uncommon for SAP implementations to cost several million £s, this could be used to build bespoke software.
There's a massive risk here though - there are thousands of ways bespoke ERP can go wrong. Underfunding the project causes problems, but arguably the worst projects were overfunded. Then there's recruiting the right people and developing the right culture - archaic business hierarchies are almost mutually exclusive with good software teams.
In other words, there isn't really a very good option. You can understand why business leaders, who are often not technology experts, would go with something that has 'worked' for them in the past.
Bespoke is expensive but sometimes the least expensive option. I worked at a company that just hired an auditing consultant firm to certify their existing system. It took a year of locking down existing processes and slapping approvals and change management on everything, but at the end the system stayed more or less the same with minimal changes in business process required. I think they made the right choice, but they had the personnel, time, size, and money to do it. I think it would have been riskier, taken longer, and been more expensive to buy an ERP (NetSuite and SAP were evaluated), and the business came to the same conclusion. However I would not recommend this for for any company with less than half a billion in revenue already!
M&A (mergers and acquisitions) is a big factor - for most large corps it happens all the time, you haven't finished integrating all your acquisitions before you get new aquisitions or get acquired yourself. So if you go the bespoke path, you have to continuously migrate departments and their data off of SAP or something like that. And when you get acquired, you'll likely have to migrate to SAP or something like that - and, more interestingly, you may come to a situation where you need to migrate to SAP or something like that before an acquisition to remove a potential risk factor for the acquirer you're targeting; that's going to cost a lot but it's worthwhile given the expected M&A money.
True! But than, when Amazon started, there was no solution for their problem, e-commerce with an integrated logistics software suite, available. Which gave Amazon a huge advabtage over competitors. That changes since a couple of years if you ask me. Which could be a problem for Amazon in the long run. Very long, so.
Out of the box, probably nothing. Something that supports all features you will actually want to use? That depends on who you are and what you actually need to do but, then, you'll need to figure out what you want, what you need and what is available on the market. This assessment is, in itself, quite costly.