If you could only invest in one, I'd say gold. As much as I love Bitcoin, its a technology in its infancy, theres no telling if its going to last long term. I think your chances of having a high return are greater with Bitcoin, however you are pretty much guarenteed at the very least some return on gold. Gold has been currency/an asset for 5,000 years. Bitcoin has been for 6 years.
If its not a one or the other choice, why not invest in both?
The context is a recommendation for a third world impoverished person. I may agree with you if you own a safe or safety deposit box but where is a local artisan or farmer going to secure their gold coins? Many don't own bank accounts , they can't afford safety deposit boxes, petty theft is rampant and they have very little privacy with living in tightly crowded pueblos and apartments with many family members(some of which are drug addicts and/or thieves)
So you do not believe that Gold will become less valuable in hmmmm maybe 15 years time?
Do you think it will be as valuable as Bitcoin? Or much lesser in value as Bitcoin?
Gold is a safer store of value than bitcoin but won't go up much in value. From an investment perspective bitcoin is riskier but will likely have much greater returns. Either way an average person in a third world country cannot properly secure the gold and thus recommending it isn't a good idea.