Yes. But there’s more to it than that.
It’s also placed well enough after the Xmas Holiday (and shopping) season that people don’t really start thinking about it until after the New Year. It poses no psychological impediment to spending money, and doesn’t place a burden on businesses to get their documentation (W-2s) together and out to employees until after the holidays at over. As well as annual budgeting exercises, etc which are usually need on calendar year or fiscal year starting Oct 1.
But, as you also point out, it’s far enough in advance of election day that the sting of it has pretty much evaporated by the time it comes to vote. In realty it’s optimally placed on the calendar to have as neutral an impact on just about any other type of annual activity except Spring Break.
There once may have been a good argument to move Tax Day closer to election day, but now it would be a disaster.
Your typical low information voter now gets a HUGE tax “refund” every year courtesy of EITC and employer overwithholding (employers which underwithhold are at risk of severe penalty ... so they withhold even from employees highly likely to have no FIT liability). This has become so predictable that the tax preparation chains now advertise Tax Day as a second Christmas. The >last< thing you want that guy thinking about it how much he LOVES Uncle Sugar.
Anyway, April 15 isn’t a bad day. We couldn’t really have an earlier tax day, because investors and business people can’t even start to prepare their returns until the accountants finish the calendar-year business-level tax calculations and give them their K-1s, 1099s, and Schedule C / Schedule D data. And a later day delays financial reconciliation for taxpayer and government alike.