It's a fair question, and the answer is "I don't know." Petrol leaf blowers are typically 2-stroke engines which are incredibly polluting (even in an absolute sense compared to a modern 4-stroke engine for a mid-sized saloon). They also kick up a lot of dust. I'm not sure what the balance is. Certainly for e.g. NO2 and hydrocarbons switching to electric will be a huge win, but I'm not sure how much/long the particulates kicked up by blowing contribute.

[edit]

I found a report[1]; on page 22, the median estimated "fugitive dust" emmisions of blowing on a shoulder, or curb is about 480g (1lb) of PM2.5 per hour. It does note that this is a pure calculation and not empirically tested though. The entire range of their calculations put fugitive dust as higher particulate emissions than the exhaust (though the exhaust particulate of a 3hp leaf-blower (i.e. high-powered commercial) is already nearly 2 orders of magnitude higher than a modern light-duty vehicle and a 0.8hp (i.e. typical personal-use leafblower)).

1: https://ww2.arb.ca.gov/sites/default/files/2018-11/Health%20...