This has been extensively discussed in another thread with no useful conclusion:
You don’t really need citizenship to achieve your goal. You might consider using an EU Blue Card, and pursuing EU Long Term resident status. If you have an employer willing to sponsor you into a country, this gets you in faster and easier, and all you need to do is stay in the EU under a Blue Card for 5 years to qualify for Long Term resident status. This status lets you stay in the EU without the job. This saves you the investment and all that. Also, if your employer gets you into the EU on Blue Card but then you leave the employer, you are still eligible to find another job anywhere in the EU to maintain your Blue Card until you achieve long term residence.
Alternatively, I would be concerned that Portugal might eventually not approve of people whose clear intention of filing for citizenship is to go live somewhere else in the EU. You are talking about making a significant investment and going through a lot of bother hoping for a potential outcome that is many years in the future. A GV is simply a way to satisfy one of the requirements for citizenship; there is no direct linkage between GV and citizenship.