Same headline, different extras
Both start at 5% plus a fixed fee per sale. Paddle stops there: it states that currency conversion and international handling are included. Lemon Squeezy adds 1.5% when the buyer is outside the US, and 1% when it pays out to a bank outside the US.
So the seller's location matters as much as the buyer's. A US seller with US buyers pays the same on both: $250.50 on a $5,000.00 sale. A European seller with US buyers pays the payout fee at Lemon Squeezy, $297.99 against $250.50. A European seller with European buyers pays both extras: 7.48% against 5.05%.
Beyond price, they aim at slightly different sellers. Lemon Squeezy is built for solo creators and small stores selling templates, courses and software. Paddle is built for SaaS companies with subscriptions and reviews each business before onboarding. Both put their own name at checkout, because they are the seller.
If most of your customers are businesses that can self-account for VAT, compare both with a plain processor too: the reverse charge can make a merchant of record unnecessary.