If I have Pounds (GBP) and I need to buy Oil and settle in Dollars (USD), I exchange my Pounds for Dollars, and then I exchange my Dollars for Oil. The price of the Oil in Dollars doesn't matter to me, only the overall price of the Oil in Pounds. It has no effect on how many Pounds I spend if the GBP:USD is weaker now than it was 1, 2 or 5 years ago, it only matters what the net GBP:Oil exchange rate is.

The only time strengthening/weakening of the Dollar can have an effect is if the price moves between the two exchanges, but given how short settlement windows are, this is somewhat irrelevant.

In a system of free-floating exchange rates and absent of supply side shocks, inflation is entirely a domestic phenomenon. The reason why the entire G7 have the same problem is because they all experienced the same pandemic, and their respective Central Banks all took the same action (to increase the money supply).

Foot notes:

[1] We have since layered a supply-side shock on top of this, which has pushed up energy prices in many currencies, but this is not because of the strengthening of the Dollar, it is because many nations wish to minimise the amount of Oil & Gas they buy from one of the largest exporters of said Oil & Gas, effectively reducing supply.

[2] A strong Dollar can cause problems when foreign nations borrow in Dollars (i.e. they borrow Dollars rather than their domestic currency). As the Dollar strengthens, this means they have to sacrifice much more of their local currency to repay the debt, which can cause significant problems. (Editors note: try not to borrow in someone else's currency if you can avoid it.)