Only you can decide that.
Like your dad, I am at the other end of the spectrum with children (young adults,) who are in similar positions to yourself. The only difference is they live with an airline pilot who is always moaning and complaining!
I and my family have undoubtably been the beneficiaries of what has been for the most part a great career. I started as a teenager and since then haven't been out of work for over 3 decades. I have never had an airline go bust under me. Progression through the ranks and fleets I wanted has been good. Salaries crossed the six figure threshold a decade ago. I am now looking forward (with fingers crossed) to a healthy final salary pension, the ability to still potentially fly for another 10 years, with all those benefits as a great big cushion. I get fed and watered at work. I get paid to be in nice hotels around the world. I get a free
finest quality polyester uniform. Free car parking in the convenient car parks at work. Free private healthcare. Free Insurance against sickness and loss of licence. Even something that helps pay for dental/eye treatments. Good travel benefits etc. I have never paid for a type rating. Never been bonded to anybody other than by loyalty.
How could I not recommend this industry that has been so good me, to my own children, or indeed anybody else? The answer to that question, is that this industry is well into the process of major change. You don't need me to point out how it has changed, just read these forums. The tide of change is working it's way up the beach. My collegues and I are an expense that will eventually dissappear and then the transformation will be complete. It is not a case of if it will happen, only when, and even that date is a reasonable certainty. In other words this job might be emblazened with the same titles, but the process of aquisition and maintenance is very different indeed.
This isn't to say the job itself is now bad or not to be recommended, however the First Officers role is becoming part of the pre-qualification process as far as reward is concerned. As a strategy, it takes a lot of cost pressure off all levels of employment for pilots. If you don't think so look at the companies who are enthusiastically engaged in the practice. Perhaps this will continue to be the way of the future, but in any event it has and will transform the reward expectations and the reward levels for this profession.
For what it is worth, I think your dads advice is very sound. One sentence in your post stood out for me:
I just don’t want to waste the better part of 70K on a career that doesn’t guarantee a job
Well it may well be a good deal more than that, and it will guarantee nothing! However if you decide that, like many others, it is a risk you feel will give you the best chance of reward, then go for it. Reward isn't just about money, but it would be naive to not suggest that money is the tool that can facilitate a better lifestyle for many people.
Nobody really knows what the future holds, but you can be sure it will be full of the unexpected. Do your research and make the decision you feel happy with.
Oh and of course listen to your dad!