Is traffic around the Las Vegas strip busy? Absolutely.
Can it be confusing? Yes.
Is it doable? Yes
This is a personal decision. If you live in a town with one stoplight, the stress of driving around there might ruin your day.
If you are from Los Angeles, Miami or Atlanta, it is likely going to be much less of a big deal.
As for parking, it is around $20 in most of the places you likely would want to go. There are a few spots with free parking, but they may be miles from where your show is. This may be fine for just a little sightseeing, but not work if you have a specific destination in mind.
Parking costs can change all the time, so I would research this shortly before your trip to see what is available. For example, Resorts World recently announced free parking until the end of August. However, you may not even want to visit there or near there.
There are other factors to consider. Are you going in the summer when it is 120 outside? Can you walk for miles? Where are the shows? Do you plan to drink? Do you want to do any sightseeing around the area?
Some people find it less painful to rent a car than to have to make multiple financial decisions to use rideshare even if the cost is not much different.
Would your vacation be more enjoyable to you if you spent $350 on Uber and were taken wherever you wanted to go vs. paying $300 to rent a car and pay for parking, but have the freedom to go whenever and wherever you wanted?
When we stayed at the Grandview, we rented a car, but we went to Hoover Dam and some other sights around the area. We paid to park twice for shows at The Strip and parked free once at Treasure Island. Having a car also allowed us to go eat at places not on the strip for much less.
If I was going to the Grandview and mainly going to Southpoint with perhaps a couple trips to The Strip I would certainly consider rideshare because of the ease and convenience.
There is no wrong answer, you just have to pick what you feel would give you the least amount of stress at the most amount of enjoyment.
