Mumbai to Goa is short enough by air (around 1 hour) that many travellers treat it as an easy long weekend rather than a full holiday requiring extensive planning. That short flight time is exactly why Goa packages from Mumbai tend to run shorter - 3-4 days - compared to Goa packages sold from cities further away.
The scenic alternative is the Konkan Railway, roughly 12 hours overnight, genuinely popular with travellers who enjoy the coastal train journey itself rather than just wanting to arrive. A road trip via NH66 covers the same coastline in about 10-12 hours and suits those combining a Goa trip with a broader Konkan coast road journey.