Along with it being an increased risk since it's generally a long term commitment with no guarantee that the market will continue to maintain the demand that requires the increased capacity.
The manufacturing of ammunition is a great example of how swings in demand needing to be a consideration in increasing total capacity. ....and Tesla can serve as an automotive example of the challenges of increasing manufacturing capacity/throughput.
Really about the only time expanding a business would seem to be "easy" is when the entire business is really small (e.g. <5-10 people).
On that note (changing the topic a bit) having just gotten the disc harrow and 16" plow
View attachment 624535 I order back in August, I'm hoping I'll get a chance test them out by expanding my gardening by putting in a 50'x100' in-ground garden this weekend (assuming weather and soil conditions cooperate). That way I can get a cover crop planted before this winter, and have more organic material in the ground for planting next spring.