The verdict
For a small B2B team selling software abroad, I would pick Paddle. You skip VAT registration and filing, and billing, payments and fraud protection come from one provider. The fee is a share of each checkout with no monthly charge, which suits an early-stage company.
Pick Chargebee when pricing is the hard part. Usage, credits, several plans and custom enterprise terms are where a dedicated billing platform helps, and a finance team may want revenue recognition handled too. You will keep your gateway and the tax work.
If your average order is small or your invoicing is heavy, ask Paddle about custom pricing early.