Tax-loss harvesting is most beneficial for those in higher tax brackets. Tax-loss harvesting is very difficult to do manually as an individual investor since you would have to constantly monitor your portfolio for losses, then reinvest your money in a new security that isn't 'substantially similar'.
Plenty uses a proprietary algorithm to do this for you automatically. Tax-loss harvesting doesn't benefit individuals who may not owe taxes for that year. Plenty is not a tax advisor; we recommend you consult a tax advisor for advice on your individual tax situation.
Please note that tax-loss harvesting is only available when using a Premium portfolio. There's no extra fee for using a Premium portfolio, but they are only available for Joint Goals.
For Plenty's disclosures on tax loss harvesting and wash sales, please see Plenty's general disclosures here.