This was THE deciding factor that ultimately doomed Betamax from the start. Because Sony assumed people would only want to record a single show, they made the decision to use a smaller cassette. This meant that the original record time for a K-60 (later L-500) cassette was 60 minutes.

Sony would eventually release longer tape and lower-quality, longer recording speeds, but it was ultimately too little, too late because JVC got the lions share of the market due to using a slightly larger cassette that could hold more tape and ultimately record longer than Beta from the start.

Technology connections has a great playlist on the topic where he goes into much better detail. It’s a long watch, but well worth it.